August test 2013

1

SEKOLAH MENENGAH KEBANGSAAN TAMAN SEAAugust Test 2013

PHYSICSForm 4(1 hour)

Name:…………………………………….. Class:……………

Answer all questions in Section A and Section B. Answer Section A in the space provided on Page 8.

g = 10 N kg-1 Momentum = mv Pressure, p = hg v2 = u2 + 2as

a = s = ut + at2 Pressure, p = Kinetic energy = mv2

Gravitational potential energy = mgh Elastic potential energy = Fx

2

Section A

1 The table shows the results of an experiment to investigate the relationship between load and extension of a spring. The diameter of the spring, d, is 1.0 cm. The original length of spring, l0, is 7.0 cm.

Load, F /N Extension, x / cm0.5 0.41.0 0.91.5 1.12.0 1.62.5 2.0

Which physical quantity is the responding variable ?

A Load, FB Extension, xC Original length of spring, l0

D Diameter of spring, d

2 An object is released from rest at an altitude of 1.0 x 107

m. What is its impact speed with the earth? Assume no air resistance and g is constant.

A 7.0 x 103 m s-1

B 8.7 x103 m s-1

C 1.1 x104 m s-1

D 1.4 x104 m s-1

3 The diagram shows a pillion rider moving backwards when the motorcycle accelerates suddenly.

The backward movement of the pillion rider can be explained byA the concept of inertiaB the concept of impulsive forceC the concept of equilibrium of forcesD the principle of conservation of energy

4 A worker is lifting boxes of identical weights from the ground to a conveyor belt. At first, it takes him 2.0 s to lift each box. Later in the day, it takes him 2.4s . Which of the following statements is correct ?

A Later in the day, less work is done in lifting each box.

B Later in the day, more work is done in lifting each box.

C Later in the day, less power is developed in lifting each box.

D Later in the day, more power is developed in lifting each box.

5 A gymnast bounces off a trampoline with a velocity of 16 m s-1. What is the maximum height he can reach?A 0.8 mB 4.0 mC 8.4 mD 12.8 m

6 Two forces, 3 N and 4 N, act on point P as shown in the diagram.

Which of the following vector diagrams show the resultant force, F, for the two forces?

B

7 The diagram shows a wooden block being pulled by a force of 10 N at an angle of 40o to the floor.

3

If the wooden block is pulled through a distance of 5 m, how much work is done on the wooden block ?

A 18.8 JB 24.4 JC 38.3 JD 50.0 J

8 A crane lifts a load of 200 kg to a height of 80m in 12 s. If the power input is 30 kW, what is the efficiency of the crane ?A 21 %B 44%C 53%D 64%

9 Assuming all the springs are identical, which arrangement will produce the smallest extension when a similar load is hung on to it ?

10 The figure shows 3 similar springs, A, B and C. Each spring extends by 2.0 cm if a load of 40N is hung on it.

What is the extension of the spring system when the load on it is 120 N ?A 6.0 cmB 9.0 cmC 12.0 cmD 16.0 cm

11 The graph shows a graph of force against extension for a spring.

What is the elastic potential energy stored in the spring when it is extended by 0.08 m?A 0.04 JB 0.08 JC 0.16 JD 0.20 J

12 All of the following will increase the stiffness of a spring made of copper wire exceptA increasing the diameter of the spring coilB increasing the diameter of the wireC decreasing the length of the springD replacing the copper wire with a steel wire

of the same diameter

13 A brick with rectangular sides rest on a table as shown in the diagram. The brick is then turned so that it rests on the table on its smallest face.

How has this change affected the force and the pressure exerted by the brick on the table ?

Force Pressure

A unchanged unchangedB unchanged increased C increased unchangedD increased increased

14 Which shoe would exert the highest pressure on the ground when worn by the same lady?

A B

120 N

0.02 0.04 0.06 0.08 1.0 x / m

F / N

4

C D

15 A girl has a mass of 50 kg. She wears a pair of shoes that cover 420 cm2 of the floor area.What is the average pressure she exerts on the floor?

A 1.2 x 104 Pa

B 1.2 x 105 Pa

C 2.1 x 104 Pa

D 2.1 x 105 Pa

16 A farmer has two carts. The carts have the same weight, but one has four narrow wheels and the other has four wide wheels. The diagram shows the two type of wheels.

In rainy weather, which cart sinks into soft ground, and why ?

Wheels ReasonA Wide Less pressure on the groundB Wide Greater pressure on the groundC Narrow Less pressure on the groundD Narrow Greater pressure on the ground

17 The diagram shows a fish in the sea. What is the pressure exerted by the water on the fish ?

[Water density = 1 000 kg m-3]

A 5 x 10 Pa

B 5 x 102 Pa

C 5 x 103 Pa

D 5 x 104 Pa

18 The figure shows three containers with different shapes filled with water to the same level. The pressure caused by the water at points P, Q and R are P1 , P2 and P3 respectively.

Which comparison is correct?

A P1 > P2 > P3

B P1 < P2 < P3

C P1=P2 = P3

19 The diagram shows the design of a dam. Why does the thickness of the dam have to be increased downwards?

A So that the dam can support its own weight.B The water pressure increases with depth.C The density of the water increases with

depth.D The temperature of the water increase with

depth.

20 The diagram shows a simple mercury barometer used to measure atmospheric pressure. Two students carry the mercury barometer from the 1st floor to the 30th floor of a block of flats

They noticed that the height of the mercury column, h, in the barometer decreases. Why is this so ?A Air pressure has decreased.B There is more air around them.C Some mercury has evaporated.D They are climbing too quickly.

21 A capillary tube filled with a drop of mercury is held in four different positions. In which

5 m

Diagram 14

5

capillary tube, A, B, C or D will the pressure of the gas inside be the highest?

A B

D

C

22 The diagram shows a manometer connected to a gas tank.

(Density of water = 1000 kg m-3. Atmospheric pressure = 100,000 Pa)

What is the pressure of the gas in the tank?

A 70 000 PaB 93 000 PaC 103 000 PaD 130 000 Pa

23 A water manometer is connected to a gas supply. The diagram shows the water levels.

If the water is replaced by mercury, which of the following shows the mercury levels when the manometer is connected to the same gas supply?[Density of water = 1 x 103 kg m-3, density of mercury = 1.36 x 104 kg m-3)

24 Which of the following is not an application of atmospheric pressure?A siphonB suction cupC vacuum cleanerD hydraulic brakes

25 The diagram shows a hydraulic brake system.A driver steps on the brake pedal.

Which relationship is correct?

A Force on piston Q < Force on piston PB Force on piston Q = Force on piston PC Pressure on piston Q > Pressure on piston PD Pressure on piston Q = Pressure on piston P

26 The diagrams show a test tube partially filled with sand, first floating in water, and then

floating in tetrachloromethane. F1 and F2 are the buoyant forces acting on the test-tubes in water and tetrachloromethane respectively.

30 cm

mercury

gasmercury

gas

mercurygas

mercury

.

gas

6

Which of the following statements about F1 and

F2 is true ?

A F1 < F2

B F1 = F2

C F1 > F2

27 A ship moves from the river to the sea. Which of the following about the buoyant force acting on the boat and the volume of water displaced by the boat is true?

Buoyant force acting on boat

Volume of water displaced by boat

A increases increasesB increases decreasesC no change increasesD no change decreases

28 The diagram shows a block of metal hanging on spirng balance in the air and the same block of metal partially immersed in water.

The reading of the spring balance with the stone in the air and partially immersed in the water is 5 N and 3 N respectively. Which of the following statements is true?

A The weight of the water displaced is 3 N.B The buoyant force acting on the metal block

is 2 N.C The weight of the metal block and the weight of the water displaced is the same.D The volume of the metal block and the

volume of water displaced is the same.

29 The diagram shows a boy on a float.

Which of the relationship between the physical quantities in the above situation is correct?

A Volume of water displaced = (volume of the boy + volume of the float)

B Volume of water displaced > ( volume of the boy + volume of the float)

C Weight of water displaced = (weight of the boy + weight of the float)

D Weight of water displaced > (weight of the boy + weight of the float)

30 Which of the following does not make use of Archimedes’ Principle ?

A A shipB A racing carC A submarineD A hot air ballon

Section B

1. The diagram below shows a hydraulic jack in a car service center. A force F is exerted on the small piston.

(a) Name the principle involved in a hydraulic jack.

(1m)

(b) The cross-sectional areas of the small piston and

the large piston are 0.05 m2 and 1.00 m2 respectively. A force of 50 N is exerted on the small piston.

(i) Calculate the pressure exerted on the oil in the hydraulic jack.

(2m)

(ii) Calculate the force exerted on the large piston by the oil.

7

(1m)

(c) State one modification to the large piston to enable the jack to lift a heavier load.

(1m)

(d) If air bubbles are found to be inside the oil, the load that hydraulic jack is able to lift is much less than that calculated in (c)(ii). Why is this so?

(1m)

2. The diagram below shows a boy and his father sitting on two identical beach balls, A and B respectively. Their weights are balanced by the buoyant force.

(a) What is the meaning of weight ?

(1m)

(b) Observe Diagrams 1 and 2. (i) Compare the weight of the boy and his father.

(1m)

(ii) Compare the volume of water displaced in these two situations.

(1m)

(iii) Compare the buoyant force in these two situations.

(1m)

(c) State the relationship between the buoyant force and

(i) the volume of water displaced

(1m) (ii) the weight of water displaced

(1m)

(d) Name the physics principle involved.

(1m)

3. A submarine descends to a depth of 70 m below the surface ot the sea. The density of sea water is 1050 kg m-3.

(Atmospheric pressure is 1.0 x 105 Pa.)(a) Calculate (i) the increase in pressure as it descends from surface to a depth of 70 m

(2m)

(ii) the total pressure on the submarine at a depth of 70 m

(1m)

(b) On another dive, the submarine experiences a

total pressure of 6.5 x 105 Pa. A hatch window on the submarine has an area of 2.5 m2. Calculate the force on the outside of the hatch cover.

(c) The submarine undergoes tests in fresh water. (i) Complete the following by ticking the correct box:

At the same depth, the pressure on the submarine in fresh water is

8

smaller than the pressure in sea water

greater than the pressure is sea water

same as the pressure in sea water(1m)

(ii) Explain your answer to 3(c)(i).

(1m)

Answer Sheet for Section A

1 =A= =B= =C= =D=

2 =A= =B= =C= =D=

3 =A= =B= =C= =D=

4 =A= =B= =C= =D=

5 =A= =B= =C= =D=

6 =A= =B= =C= =D

7 =A= =B= =C= =D=

8 =A= =B= =C= =D=

9 =A= =B= =C= =D=

10 =A= =B= =C= =D=

11 =A= =B= =C= =D=

12 =A= =B= =C= =D=

13 =A= =B= =C= =D=

14 =A= =B= =C= =D=

15 =A= =B= =C= =D=

16 =A= =B= =C= =D=

17 =A= =B= =C= =D=

18 =A= =B= =C= =D=

19 =A= =B= =C= =D=

20 =A= =B= =C= =D=

21 =A= =B= =C= =D=

22 =A= =B= =C= =D=

23 =A= =B= =C= =D=

24 =A= =B= =C= =D=

25 =A= =B= =C= =D=

26 =A= =B= =C= =D=

27 =A= =B= =C= =D=

28 =A= =B= =C= =D=

29 =A= =B= =C= =D=

30 =A= =B= =C= =D=

Prepared by :………………………………… Ms Wong Yin Lee

Approved by:………………………………… (Pn. Zakiah Mohd Nor)