Section 1 Mechanics

8/13/2019 Section 1 Mechanics

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Section 1: MechanicsPast papers

2005 June

Q1-(a) A student wants to use metal wire as part of a model bridge that she is building.To test if a wire is suitable she hangs a mass of 0.5 kg from it and measures itsextension. Calculate the weight in newtons of the 0.5 kg mass.

......................................................................................................................................

............................................................. Weight = ........................... N (2)(b) She continues to add masses to the end of the wire. The graph shows the results ofher experiment.

(i) Indicate on the graph the region associated with Hookes law. (1)(ii) Explain your answer.

...............................................................................................................................

........................................................................................................................(1)(c) The student thinks the wire is too weak and decides to replace it with a thicker wireof the same material and length. She tests it in the same way as before by hangingmasses from its end.Show her possible results on the axes above. (2)

(Total 6 marks)

Khalid Mazhar Qureshi www.edexcel-cie.com


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Answer:Q1 (a) 5 N 4.9 using 9.8

W = m x g (1 mark) or w = 0.5 x 10 (1 mark)2

(b) (i) indicates initial linear region(ii) The region indicated is linear/ extension is proportional 1to weight OWTTE 1

(c) (straight) line through origin of shallower slope thanExisting straight line (1 mark)

Straight line continues beyond weight associated withElastic limit for thinner wire (1 mark)

2Total 6 marks



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Q-9: On a day when there is no wind, a rock falls from a very high cliff. It does not hitanything until it reaches the ground.(a) Give the name and direction of each of the two forces, apart from upthrust, which acton the rock as it falls.

1 ...................................................................................................................................

2 ...................................................................................................................................(2)

(b) One of the forces which acts on the rock changes significantly as the rock falls.Name the force and explain what happens.

......................................................................................................................................

..................................................................................................................................(2)(c) The mass of the rock is 450 kg. At one point in its fall the unbalanced force on the

rock is 60 N.Calculate the acceleration of the rock at this point and include its unit.

......................................................................................................................................

......................................................................................................................................

................................................... Acceleration = .............................. (3)(d) After some time, the falling rock reaches its terminal velocity.(i) Describe the motion of the rock when it is at terminal velocity.

.............................................................................................................................. (1)(ii) State the size of the unbalanced force on the rock as it falls at terminal velocity.

.............................................................................................................................. (1)

(Total 9 marks)



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2005 Nov

Q3:A teacher suspends an object from a clamp. She places a small screen in front ofthe object so that the students cannot see it. She then attaches a mass to the bottom ofthe object. The mass applies a force to the object and the object extends.

(a) Different masses are attached to the bottom of the object.The teacher measures the extension and the students calculate the value of the appliedforce.

The table shows the results.

Plot the points on the grid. Draw the best straight line through the plotted points.



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(3)

(b) Use your graph to find the extension for a force of 8.0 N.

................................................................................................................................. (1)

(c) Explain why the extension for a force of 800 N is unlikely to be one hundred timesthe value in (b).......................................................................................................................................

...................................................................................................................................(1)(d) The teacher tells her pupils that the object is one of three things:

a helical spring

a metal wire

an elastic band.

(i) Which one could it be?

............................................................................................................................(1)(ii) Give two reasons for your choice.1 .............................................................................................................................2 .........................................................................................................................(2)

(Total 8 marks)



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Answer



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Q-9: (a) A cart becomes stuck in a river bed. A group of people gets it moving again.Some of them push and some of them pull.

The diagram shows the horizontal forces which act on the cart.

(i) Complete the sentences.

The frictional force is force ...........

The pushing force is force .......... and the pulling force is force ........... (1)(ii) Forces are vectors. How does the diagram show this?...............................................................................................................................

............................................................................................................................ (1)(iii) Force U is the unbalanced force which acts on the cart. Complete the equationfor force U in terms ofX, Y and Z.

U = ......................................................................................................................... (1)(b) A cart has a mass of 1500 kg. An unbalanced force of 1125 N acts on the cart in aneasterly direction.Calculate the acceleration of the cart and state its unit and direction.

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

Acceleration = ................................................... (4)

(Total 7 marks)



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Answer



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2007 June

Q-1:A model train travels between two stations. The velocitytime graph shows the trains

motion.

(a) (i) State in which part of the journey A, B or C the train is decelerating.

.......................... (1)

(ii) Explain your answer.

............................................................................................................................... (1)(iii) What does the graph show about the deceleration?

............................................................................................................................... (1)(b) (i) What feature of the graph represents the distance travelled between the twostations?

............................................................................................................................... (1)(ii) A second train travels between the two stations at a constant velocity. It takes the

same time as the first train. On the axes above, draw a line showing the motion

of the second train. (3)

(Total 7 marks)



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8. (a) State the principle of moments.

......................................................................................................................................

......................................................................................................................................

................................................................................................................................. (2)

(b) The diagram shows a weighing device called a steelyard.

The weight of the shoulder balances the weight of the arm. The weight of the rider is

8.0 N and this balances the weight of the load whenx = 0.12 m and y = 0.60 m.

Calculate the weight of the load in newtons.

......................................................................................................................................

......................................................................................................................................

Weight of load = .................. N (2)

(Total 4 marks)



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Q-12. (a) The diagram shows a lorry. It is travelling in a straight line and it is accelerating. The

total forward force on the lorry is F and the total backward force is B.(i) Explain which is larger, force F or force B.

...............................................................................................................................

............................................................................................................................... (1)

(ii) State an equation which relates acceleration, mass and unbalanced force.

............................................................................................................................... (1)(iii) An unbalanced force of 15 000 N acts on the lorry. The mass of the lorry is

12 500 kg. Calculate the lorrys acceleration and give the unit.

...............................................................................................................................

...............................................................................................................................

Acceleration = .................................. (3)

(b) Another lorry is travelling at a steady speed. Explain how this lorry can be accelerating

even though its speed stays the same.

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

.................................................................................................................................... (3)

(c) The thinking distance is the distance which a vehicle travels in the drivers reactiontime. The braking distance is the distance which a vehicle travels when the brakes

are on.

(i) State one factor which increases the thinking distance.

...............................................................................................................................

............................................................................................................................... (1)

(ii) State one factor which increases the braking distance.

...............................................................................................................................

............................................................................................................................... (1)

(Total 10 marks)



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2007 Nov(a) Complete the sentence.

Hookes law states that a force acting on a material produces an extension which is

............................................................. to the force. (1)

(b) A student attaches a load to the end of a spring.

(i) Name the type of force acting in the stretched spring.

............................................................................................................................... (1)(ii) The student measured the length of the spring for different loads.

The table shows her data.

1. Deduce the load in newtons that would produce a length of 130 mm.

Load = ................................. N (1)2. Estimate the maximum load in newtons at which the spring obeys Hookes

law.Maximum load = .................................. N (1)(c) A forceextension graph for a material is shown. Three regions A, B and C are

labelled.



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(i) In which region is Hookes law obeyed?

.......................... (1)(ii) In which region is the material easiest to extend?

.......................... (1)

(iii) Explain your answer to (ii).

...............................................................................................................................

...............................................................................................................................

............................................................................................................................... (1)

(Total 7 marks)



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Answera) (directly) proportional (1)b)

(i) tension / weight / gravitational force(1)(ii) 2.5 (N) (1)(iii) 4.05.0 (1) (3)

c)(i)A (1)(ii) B (1)(iii) large extension for small increase in force (1) (3)

Total 7 marks



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12. A fishing boat is floating on the still water of a deep lake.

The fisherman drops a heavy anchor into the lake. The anchor falls through the water and

does not hit anything until it reaches the bottom.

(a) Three forces act on the anchor as it falls through the water.(i) One of these forces is upthrust. State the name and direction of the other two

forces.

1 .............................................................................................................................

2 ............................................................................................................................. (2)(ii) Which of the three forces changes significantly as the anchor falls?

...................................................

State how and why it changes.

...............................................................................................................................

............................................................................................................................... (2)

(b) The mass of the anchor is 12 kg. At one point in its fall the unbalanced force on the

anchor is 15 N.Calculate the acceleration of the anchor at this point and give its unit.

......................................................................................................................................

......................................................................................................................................

Acceleration = .......................................................... (3)(c) After a short time the anchor reaches its terminal velocity.

(i) Describe the motion of the anchor when it is at its terminal velocity.

...............................................................................................................................

............................................................................................................................... (2)

(ii) State the size of the unbalanced force on the anchor as it falls at its terminalvelocity.

............................................................................................................................... (1)

(Total 10 marks)



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Answers(a)(i) weight down(wards) (1) or (force of) gravity down(wards)(water) resistance / drag / friction up(ward) (1) orin opposite direction (to the movement / motion)Notes - both force and direction for each either order

(ii) (water) resistance / drag / friction increases (1)as speed/velocity increases (1) (depends on previousso do not credit unless first mark gained) (4)

(b)1.25 (2) or F = ma (1) or (a) = 15 12 (1) m/s2 or ms-2 (1) (3)(c)(i) down(wards) (1) at a steady speed (1)or no acceleration / deceleration (2)or constant velocity (2)(ii) zero/0(N) (1) (3)



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2008 June

Q-1:(a) A child runs out in front of a car. The driver makes an emergency stop. The graph

shows the speed of the car from the time when the driver sees the child on the road.

(i) State the drivers reaction time in seconds.

Time = ................................... s (1)

(ii) State the time in seconds for the brakes to stop the car.

Time = ................................... s (1)

(iii) Draw two more lines on the grid above to show how the speed might change ifthe driver has been drinking alcohol and the road is slippery. (2)

(b) The condition of the tyres and the condition of the road surface are two factors which

affect the force of friction on a car.

(i) Name one other factor which affects the force of friction on a car.

............................................................................................................................... (1)(ii) The diagram shows a car. The centre of gravity of the car is at the point

labelled X.

Add to the diagram an arrow showing the weight of the car. (1)



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(Total 6 marks)



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Q. No Correct Answer Acceptable Ans. Marks1 (a)(i) 0.8 (seconds) 4/5 second

8/10 second1

(1)1 (a)(ii) 3.2 (seconds) 3 1/5

allow ecf from (i)

4.0previous answer

1

(1)1 (a)(iii) one line

horizontal line beyond 0.8

less steep slope down (to thex axis)

dop

two separate lines orone of these lines

labelled 1 mark for each

correct

1

1

(2)1 (b)(i) air (resistance)

mass of car

speed (of the car)

brakes

tyre pressure

area of tyre

streamlining

Drag

Weight

(force of) gravity

Size

Shape

velocity (of car)

REJECTED ANSWERwind (resistance)

temperature

1

(1)

1 (b)(ii) intentionally straight vertical arrowpointing downwards

from, above, below or through point

X

arrow from middle of

car1

(1)



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Q-9:(a) A boy jumps off a wall and lands on the ground without bending his knees. The graph

shows how the velocity of the boy varies with time as he lands.

(i) What property of a velocity-time graph can be used to determine acceleration?

............................................................................................................................... (1)

(ii) Use the graph to calculate the boys deceleration and give its unit.

...............................................................................................................................

...............................................................................................................................

Deceleration = .......................................................... (3)

(iii) The mass of the boy is 70 kg. Calculate the resultant force in newtons acting onthe boy.

...............................................................................................................................

...............................................................................................................................

Force = ................................ N (3)(b) Explain why the boy should bend his knees as he lands.

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

(3)

(Total 10 marks)



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Q. No. Correct Ans. Acceptable No. Rejected Marks9 (a)(i) gradient slope area 1

9 (a)(ii) 6.0 0.25 = 24

m/s2

or m/s/s or ms-2

ignore minus signs

N/kg or Nkg-1

3

9 (a)(iii) F = m a= 70 24

= 1680 (N)

ecf from (a)(ii)nwn

70 x 10700 x 24

score 0/3

3

9 (b) any three pointssame change in velocity(in) more timeless acceleration ordeceleration oraless force ora

comes to a stopover a longerdistance

24 ms-2

is toohighallow slowerdeceleration

damage to joints

effect of area ofcontact andpressure

impact reduced

1

1

1

(3)



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Q11-C:(c) The students also saw a material being stretched.

The graph shows the results.

(i) Name a material which would produce these results.

............................................................................................................................... (1)

(ii) Indicate on the graph the region associated with Hookes law. (1)(iii) Explain your answer.

...............................................................................................................................

............................................................................................................................... (1)

(Total 12 marks)



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ANSWER

Q. No Correct Ans. Acceptable Ans. Mark

11 (c)(i) metalany metal

ignore spring

metal spring

metal wire1

11 (c)(ii) linear region correctly marked 1

11 (c)(iii) dopproportionality between force(or

mass or load or weight) and

extension OWTTE

elastic behaviour 1

(Total 12 marks)



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2008 Nov

Q6:The diagram shows a barrier at a car park. The barrier arm is usually in the position

shown. An iron sphere is attached to the barrier arm at A. The weight of the barrier armacts at B. When there is a current in the coil the barrier arm pivots at P and end E moves

upwards.

(a) At which point, A, B, E or P, is the centre of gravity of the barrier arm?

Point ................ (1)(b) Complete the sentence.

The coil acts as an ...................................................... (1)(c) Why is the coil made of insulated wire?

......................................................................................................................................

...................................................................................................................................... (1)(d) What is the cause of the force on the barrier arm at Abefore the electricity is switched

on?

...................................................................................................................................... (1)



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(e) When the electricity is switched on the total force which acts at A is 900 newtons.

This force can just start to pull the iron sphere down.

Use the distances shown on the diagram to calculate the weight in newtons of thebarrier arm.

Show your working.

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

Weight of barrier arm = ....................... N (3)

(Total 7 marks)



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Answer

6a- B (1)

6b-Electromagnet (1)

6c-to prevent shorting/a short circuit /to prevent current (accept electricity) from going directlyfrom one turn to the nextaccept from one coil to the nextdo not credit any reference tosafety/electricshock/heatinsulation



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Q13:During a storm, a large rock falls from a high cliff into the sea.

The graph shows the velocity of the rock as it falls from the cliff until it reaches the bottomof the sea. A, B and C are stages in its fall before it hits the sea.

(a) State the property of the graph that can be used to determine

(i) acceleration,

............................................................................................................................... (1)

(ii) distance travelled.

............................................................................................................................... (1)

(b) (i) Does the rock reach terminal velocity in air? (1)

...............................................................................................................................



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(ii) Explain your answer.

............................................................................................................................... (1)

(c) A, B, C, D and E represent stages in the fall of the rock.

At which of these stages does the rock have

(i) greatest acceleration, ............................. (1)

(ii) greatest deceleration, ............................. (1)

(iii) the greatest force acting on it due to air resistance? .............................. (1)

(d) Describe and explain the motion of the rock when it is in the sea at stage E. Use theconcepts of drag, weight, acceleration and velocity in your answer.

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

...................................................................................................................................... (4)

(e) Explain how the graph shows that the height of the cliff is greater than the depth ofthe sea.

......................................................................................................................................

...................................................................................................................................... (2)

(Total 13 marks)



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Answer13 (a) (i) slope/gradient13 (a) (ii) area (under graph)13 (b) (i) no13 (b) (ii)dop graph not horizontal or velocity not constant or (still) accelerating13 (c) (i)A

13 (c) (ii) D13 (c) (iii) C

13 (d) constant velocity

weight downwards/drag upwards

equal

no acceleration13 (e) greater area under graph before sea



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14. (a) Complete the sentence.

A scalar quantity has size but a vector quantity has both size and

................................................ (1)

(b) Identify the quantities in the table as either scalar (S) or vector (V). The first two have

been done for you.Quantity Type

Speed S

Force v

Displacement

Density

Energy

Acceleration

(c) A student going to university pulls a large suitcase along the ground. The diagramshows three forces acting on the suitcase.

Calculate the unbalanced force in newtons and state its direction.

Unbalanced force = .............................................. N

Direction ................................................................... (2)

(Total 5 marks)



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2009 June

Q8-The diagram shows the sizes of the two horizontal forces, X and Y, acting on a roadtanker.

(a) Force is a vector quantity.

What does this mean?

...................................................................................................................................... (1)

(b) The unbalanced force is sometimes called the resultant force.

Complete the equation for the unbalanced force on the road tanker.

Unbalanced force = ........................................................................................................ (1)

(c) A student writes this list of quantities.

acceleration density energy mass temperature volumeThe student says they are all scalar quantities.

Do you agree with the student? Explain.

......................................................................................................................................

...................................................................................................................................... (2)

(Total 4 marks)



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AnswerQuestion Number Acceptable

AnswersExtraInformation

Reject Mark

8 (a) hassize/magnitude/(quantitative) value/quantity/amountanddirection

either order unit 1

Question Number AcceptableAnswers

Extra Information Mark

8 (b) (unbalanced force=) X-Yor in wordse.g. forward force

backward forceforward force -drag

1



8 (c) acceleration is avectororacceleration is nota scalar

acceleration andany one otherfrom the list arevectors/not scalarsscores 1

2



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(c) A student uses the graph to calculate the distance travelled by the train.

She writes the equation shown in the box.

State the correct unit in this equation for D.

...................................................................................................................................... (1)

(Total 7 marks)



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AnswersExtra Information Mark

12 (a)(i) acceleration =change invelocitytime (taken)a = (v u) /t

or any correctly transposedversionallow speed instead ofvelocity

1

12 (a)(ii) correct pair ofreadings fromthe graphe.g. 45 m/sand 30minutes45/1800 =0.025nwn

m/s

2

45/30 = 1.5nwnm/s/min

45/0.5 = 90nwnm/s/h

111


Ignore Mark

12 (b) 50 m/s scores 2marksorconstant velocitysteady speeduniform motionornot acceleratingscores only 1 mark

terminal velocity 21

12 (c) km or kilometre 1



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Q13-The diagram shows the forces which act on a coconut as it falls from a tall palm tree.

There is no wind.

(a) (i) Explain in terms of the forces involved why, at first, the coconut accelerates.

...............................................................................................................................

............................................................................................................................... (1)

(ii) Name the friction force which acts on the coconut as it falls.

............................................................................................................................... (1)

(iii) What happens to the friction force as the coconut accelerates?

............................................................................................................................... (1)

(iv) Name the term used for the downwards speed of the coconut when the friction

force equals the coconuts weight.

............................................................................................................................... (1)

(b) (i) State the equation which relates kinetic energy, mass and speed.

............................................................................................................................... (1)

(ii) The mass of the coconut is 0.80 kg. Just before it hits the ground its kineticenergy is 32.4 J.

Calculate its speed just before it hits the ground and state the unit.

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

Speed = ............................................. (3)

(Total 8 marks)



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AnswersIgnore Mark

13 (a)(i) weight/gravity isgreater thanfriction/dragoraordownward forcegreater thanupward forceora

upthrust 1

13 (a)(ii) air resistanceair frictiondrag

upthrustwind

1

13 (a)(iii) increases

(gets) bigger(gets) largerbuilds up

1

Question Number Acceptable Answers Reject Mark

13 (a)(iv) terminal velocityterminal speed

1



13 (b)(i) (kinetic energy) =

mass speed

2

or (KE) = m v2

or any correctlytransposedversion

1

13 (b)(ii) 32.4 = 0.80

v2

v = 9 nwnm/s ormetres/second

v2

= 81 or v = 81

scores 1st

mark

111



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2009 Nov

Q7: The diagram shows a tower crane on a building site.

(a) The crane is in equilibrium.(i) What does the term equilibrium mean?

...................................................................................................................................... (1)

(ii) Calculate the weight, in kN, of the load.

......................................................................................................................................

......................................................................................................................................

Weight = .................................. kN (2)

(b) (i) Weight is a vector quantity.

Explain how you can tell this from the diagram.

............................................................................................................................... (1)

(ii) Give another example of a vector quantity.

............................................................................................................................... (1)

(Total 5 marks)



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Q12-Crash tests are used to measure the safety of new car designs. In one type of test, a car

accelerates along a straight and level track and then crashes into a barrier.

a)The velocity-time graph shows one set of results



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Use information from the graph to answer the questions.

(i) Calculate the acceleration of the car from the start to the barrier.

Show your working and give the unit.

...............................................................................................................................

...............................................................................................................................

Acceleration = ......................................... (3)

(ii) Calculate the distance in metres the car travels from the start to the barrier.Show your working.

...............................................................................................................................

...............................................................................................................................

Distance = ..................................... m (3)

(iii) The car hits the barrier and a short time later it stops.

How long in seconds is this short time?

...............................................................................................................................

Time = ....................................... s (1)

(b)(i) State the equation which relates acceleration, mass and unbalanced force.

............................................................................................................................... (1)

(ii) When another car hits the barrier, it experiences an unbalanced force of 25 000 N

and decelerates at 20 m/s2.Calculate the mass in kilograms of the car.

...............................................................................................................................

Mass = .................................... kg (2)

(Total 10 marks)



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Answer

QuestionNo.

Acceptable Ans. Extra information Marks

12 (a)(i) 2 0 (2) m/s2 (1) or m s-2or m/s/sallow for (1) 28 1.4 or anyother correct indication that theslope of the ascending line isbeing used

3

12 (a)(ii) 19.6 (m) (3) orclear indication that the distanceis given by the area under (themain part of) the graph(1)a numerical statement which, ifcorrectly evaluated, leads to19.6 e.g. 1.4 28 (1)

3

12 (a)(iii) (0).06 (s) 1

12 (b)(i) (unbalanced) force = mass acceleration or F = maor any correctlytransposed version

1

12 (b)(ii) 1250 (kg) (2) or 25000 20 (kg) (1) 2



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2010 June

Q2: A child runs out in front of a truck. The driver makes an emergency stop.

The graph shows the speed of the truck from the time when the driver first sees thechild.

(a) (i) State the time, in seconds, for the driver to react.

Time = ................................... s (1)

(ii) Calculate the time, in seconds, for the brakes to stop the truck.

Time = ................................... s (1)

(b) The driver had been drinking alcohol. State the effect this may have had on:

(i) the time for the driver to react;

............................................................................................................................... (1)

(ii) the time for the brakes to stop the truck.

............................................................................................................................... (1)



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(c) Give one feature of the road conditions which may increase the stopping distance of

a vehicle.

...................................................................................................................................... (1)

(d) The diagram shows a truck.(i) The centre of gravity of the truck and its load is at the point labelled C.Add to the diagram an arrow showing the total weight. (1)

(ii) State the name of a force which opposes the motion of the truck.

.............................................................................................................................. (1)

(Total 7 marks)



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Answer

Question

No.

Acceptable Answer Extra Info. Marks

2(a)(i) 1.6 (s) 12(a)(ii) 4.4 (s) 1

2(b)(i) increase(d)/longer /more dna slower/slowed itdown 1

2(b)(ii) no effect/no change/stays the same/no difference/none/nothing

1

2(c) wet/slippery/icy/greasy/ loosesurface/muddy /snow/rain/smooth /gravel /oil

dna poor condition of thetyresor brakes

1

2(d)(i) Single straight arrow pointingdownwards and on a vertical linethrough C

judge by eyeignore labels

1

2(d) (ii) friction (between lorry and air)/airresistance/drag

dna wind resistance 1



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Q16:The diagram shows a kite in the air and the size and direction of the forces which

act on it.

(a) Calculate the resultant upward force, in newtons, on the kite.

......................................................................................................................................

Resultant upward force = ..................................... N (1)

(b) Calculate the resultant sideways force, in newtons, on the kite and state its direction.

Resultant sideways force = ..................................... N

Direction ......................................... (2)

(c) The air temperature is 17 C.

Temperature is a scalar quantity.

Explain what is meant by a scalar quantity.

......................................................................................................................................

...................................................................................................................................... (2)

(d) State the word which is used to describe quantities, such as force and acceleration,which are not scalar quantities.

...................................................................................................................................... (1)

(Total 6 marks)



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Answer

QuestionNo.


16(a) 1.0 (N) 216(b) 1.5 (N)

right/arrow drawn to right i.e./east

2

16(c) has size/magnitude/amount

but no direction

mark independentlyhas only size/magnitudescores both marks

1

116(d) vector 1



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2010 Nov.

Q5: A ticker timer is a device which makes dots on a paper tape.

A student fastens one end of the tape to a toy car and uses the ticker timer to record themotion of the toy car.

Her investigation is shown below.

Part of the tape from the students investigation is shown in the following drawing.

(a) (i) The ticker timer produces dots at a steady rate of 50 dots per second.

Calculate how long, in seconds, it took the toy car to travel from A to B.

...............................................................................................................................

...............................................................................................................................

Time taken = ....................... s (2)

(ii) Distance A to B is 73 mm.

Calculate the average speed, in mm/s, of the car as it travelled this distance.

...............................................................................................................................

...............................................................................................................................

Average speed = ...................................................... mm/s (2)

(b) The diagram shows the toy car and the arrow shows where its weight acts.

Put an X on the diagram to show the position of the centre of gravity of the car.The centre of the X should be at the centre of gravity.



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(1)(Total 5 marks)



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Answer

Question

No.


5(a)(i) 0.1 (s) or 1/10 (s) allow (1) for a time

interval of five

2

5(a)(ii) 730 mm/s allow ecf from part ai

allow (1) for clear

indication

that

(average) speed

= distance time

(taken)

2

5(b) centre of X at the start of the

downwards arrow

judge by eye 1



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Q8:A dockside crane is used to load containers onto a ship.

The jib is designed so that its weight is equally balanced on each side of the support.The following diagram shows the other turning forces on the jib.

The jib is in equilibrium.

(a) (i) State the principle of moments for a system which is in equilibrium.

...............................................................................................................................

............................................................................................................................... (1)

(ii) Use the principle of moments to calculate the weight, in kilonewtons, of theconcrete block.

...............................................................................................................................

...............................................................................................................................

...............................................................................................................................

Weight of the concrete block = .................................... kN (2)

(b) Another container weighs 26 000 N.(i) State the equation which relates weight, mass and the gravitational field

strength, g.

............................................................................................................................... (1)



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(ii) Calculate the mass of this container.

Show how you arrived at your answer and state the unit.

g = 10 N/kg

...............................................................................................................................

...............................................................................................................................

Mass of container = ................................................. (3)

(Total 7 marks)



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Q9: The photograph shows two people pushing a car.

They have to push the car with a large force before it just starts to move.

(a) Name the type of force that opposes motion.

...................................................................................................................................... (1)

(b) When the car is moving the unbalanced force acting on the car is 150 N.(i) State the equation which relates unbalanced force, mass and acceleration.

...............................................................................................................................

............................................................................................................................... (1)

(ii) What does the term unbalanced force mean?

...............................................................................................................................

............................................................................................................................... (1)

(iii) The mass of the car is 1200 kg.

Calculate the acceleration of the car and state its unit.

...............................................................................................................................

...............................................................................................................................

Acceleration .............................................. (2)



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(c) The velocity-time graph shows how the car moves from rest during ten seconds.

Explain whether the graph supports your answer in (b)(iii).

......................................................................................................................................

......................................................................................................................................

...................................................................................................................................... (2)

(Total 7 marks)



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Answer

QuestionNo.


9(a) friction allow drag/air resistance 1

9(b)(i) F = ma or any transposed versionwords or symbols 1

9(b)(ii) reference to net/resultant force

or difference in the forces acting

or push forcefriction

ignore not balanced and total 1

9(b)(iii) a = 150/1200 = 0.125

m/s2

allow 1/8

ignore N/kg

11

9(c) slope = acceleration

slope shown to be about 0.125

or use of any v/t from graph

or use v = at (1) and compare

with v value from graph (1)

ecf from (b)(iii)

1

1

Section 1 Mechanics

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