Transcript
Energy, Force, and Motion identifying energy transformations; Identifying and analyzing the transfer of heat energy by conduction, convection, and radiationinterpreting a phase diagram; describing and calculating velocity and acceleration;comparing Newton’s three laws; calculating mechanical advantage; understandingthe work of simple machines
Waves, Electricity, and Magnetisminvestigating light and sound phenomena and comparing light to sound; Doppler effect; describing the causes of static electricity; constructing and analyzingseries and parallel circuits; describing the relationship between voltage, current andresistance and relating electricity and magnetism and common applications
SPEED
Describes how fast an object is moving.
Average Speed =distancetime
Velocity The speed of an object in a certain direction.
Velocity
V = velocity (meters/second)d = distance (meters)t = time (seconds)
d V = tspeed of an object in a certain direction.
Velocityspeed of an object in a certain direction.
seconds
0
2
13
Speed=? Velocity=?
16 meters
12 meters
20 meters
Total time=4 seconds
Numerator
Denominator
512
Acceleration
Acceleration is how quickly velocity changes over time.X L eh ray shun
Speed
0
2
13
Meters/second
Accelerationhow quickly velocity changes over time.
A = (Vfinal - Vinitial) time
___________
Acceleration the change in velocity over time.
Acceleration = change in velocitytime
(v2 – v1 )Acceleration =Time
________
V1 = beginning velocity V2 = ending velocity
The graph below relates speed and time of four cars (1, 2, 3, and 4) traveling along a straight highway.
Which two cars move with zero acceleration?
1 and 4
2 and 3
1 and 2
3 and 4
Which of the following is certain to change as a ball accelerates?
mass of the ball
inertia of the ball
velocity of the ball
force acting on the ball
What must happen to an object in order to accelerate it?
A net force must be applied.
Some weight must be removed.
Its frictional coefficient must be reduced.
It must contain momentum.
Which of these describes the object with the largest
acceleration ?
An object with a small change in velocity over a small change in time
An object with a small change in velocity over a large change in time
An object with a large change in velocity over a small change in time
An object with a large change in velocity over a large change in time
Scalar a measurement that does NOT contain direction. Egg sample: Speed
Vectora measurement that contains
direction.Egg sample: Velocity
Forces of NatureGravitational Magnetic
Mass and Inertia
The universe consists of matter in motion
The greater the mass the harder it is to move. And . . .the harder it is to stop moving.
Lower mass objects are easier to move . . .and to stop moving.
NEWTON’s Laws 1st Law of Motion :
An object remains at a
in a ,until a net force acts on it.
constant speed straight path
ih ner shahAn object willremain at a
constant speed (unless
disturbed).
NEWTON’s 1st Law of Motion is the law of
the mass times velocity of an objectp = m • v
Momentum = mass x velocity (Kgrams) (meters/second)
the force of a moving body.
Higher mass higher momentumHigher velocity higher momentum
Momentum = mass x velocity
p = m • v
includes velocity. So, it has direction. Momentum points in the direction of motion.
Conservation of momentumWhen objects collide, all of the momentum goes somewhere.
Conservation of momentumWhen objects collide, all of the momentum goes somewhere.
Conservation of momentumWhen objects collide, all of the momentum goes somewhere.
Conservation of momentumWhen objects collide, all of the momentum goes somewhere.
NEWTON’s2nd Law of Motion : An object that
has a force acting on it will change its speed (accelerate).
NEWTON’s2nd Law of Motion : f = m•a
f = net force (newtons)m = mass (Kilograms)a = acceleration (meters/second2)
force = mass • acceleration
NEWTON’s2nd Law of Motion :
f = m•aacceleration of the club
force of the club
mass of the club
Net force is the total amount of Force (minus the forces that cancel each other out). Force of gravity
Force of musclesNet force
When the net force is Zero.-> NO movement
When the net force is NOT Zero.-> movement
2 Kg ?
Static Equilibrium Balanced forces When all forces are balanced. The net force is Zero. There is NO movement.
3 Kg
50 N100 N
100 N
50 N
50 N
50 N
NEWTON’s 3rd Law of Motion:
For every action there is an equal and opposite reaction.
NEWTON’s 3rd Law of Motion:
For every action, there is an equal and opposite reaction.
NEWTON’s 3rd Law of Motion:
For every action, there is an equal and opposite reaction.
Balanced or unbalanced?Action
Reaction
Gravity Inertia Friction
Gravity balancedUN
Time (mSec)Sp
eed
(m/s
) BALL
Ground
Inertia balancedUN
Time (mSec)Sp
eed
(m/s
)BALL
PUTTER
Friction balancedUN
Time (Sec)Sp
eed
(m/s
)
SKATE
A car is traveling down a hill. Which of the following will affect the amount of energy the car has?
how long the car is
the time of day
how much the car weighs
the color of the car
Friction the resistive force that occurs
when two surfaces travel past each other.
causes physical deformationgenerates heat
Friction the resistive
force that occurs when two surfaces contact each other.
Oliver the dog doesn't want to walk in the rain. He can make his owner pull harder on the leash to
get him out the door by
sitting on the vinyl floor. sitting on the tile floor.
sitting on the carpeted floor. sitting on the wood floor.
Pauline needs to measure the sliding friction of a brick. How should she go about doing this?
attach the brick to a string and then to a spring scale and read the force needed to quickly lift the brick off the ground
drag the brick by a string attached to a spring scale so that it gradually speeds up
drag the brick by a string attached to a spring scale along the surface of a table at a constant speed and read the force
hang the brick from a string attached to a spring scale and read the force
Sliding friction-the drag force created when the surface of one object slides across the surface of another object.
Sliding Friction LabObjectSurfaceforce (Newstons)
terminal velocity gravity will accelerate an object until air resistance (friction) does not allow it to go any faster.
In the absence of air resistance, which of these objects will fall at the fastest rate when dropped?
the ball with a mass of 75 kg
the ball with a mass of 25 kg
the ball with a mass of 10 kg
They all fall at the same rate.
Pressure is the amount of force exerted over a certain area.
Pressure = ForceArea
Pressure = Force (newtons) Area (m2)
1 Pascal = 1 Newton/meter2
W = f • d
{Distance
Force
{Distance
Gravitational force
Gravitational force
Gravitational forceo INCREASES with Masso DECREASES with Distance
All objects in the universe are attracted to each other by the force of
effort.
friction.
gravity.
inertia.
Four pairs of objects have the masses shown below. If the objects in each pair are the same distance apart, the gravitational force between the objects in which pair is greatest?
1 kilogram and 1 kilogram
1 kilogram and 2 kilograms
2 kilograms and 1 kilogram
2 kilograms and 2 kilograms
As an astronaut travels from Earth to a space station orbiting Earth, what happens to her mass and weight?
Her mass decreases, but her weight remains the same.
Her mass increases as her weight decreases.
Her mass remains the same, but her weight decreases.
Her mass decreases and her weight also decreases.
Which hill would you slide down the fastest?
hill A
hill B
hill C
It would take the same time to slide down all of the hills.
Projectile Motion
seconds
0
2
13
Velocity (m/s)forward downward
050 9.819.629.439.2
Projectile Motion
seconds
0
2
13
Velocity (m/s)forward downward
050 9.819.629.439.249 48 47 46
Simple Machines and work
Lever Inclined plane Pulley Wedge Screw Wheel and axle
Simple Machines• Pulley• Wheel &
Axle• Lever• Inclined plane• Screw• Wedge• Gear
Simple MachinesPulley
Wheel & Axle
Lever
Inclined plane
Screw
Wedge
Gear
Which activity involves the use of a simple machine?
riding on a seesaw
flying a kite
listening to a radio
skiing down a hill
Simple Machine
A mechanism that lowers the amount of force needed to do work, by increasing
the distance.
On which simple machine is a fulcrum found?
pulley
wheel
axle
lever
ALL Simple Machineswork the same way
1 meter2 meters
Lever action
Force=13 N Force= ?
3 meters9 meters
Mechanical Advantage= final distance starting distance
2 meters8 meters
Mechanical Advantage= distance distance
Which of the following is often used as a lever?
file
nail
saw
crowbar
The Wedge
The bottom of this light bulb is an example of what type of simple machine?
a lever
a pulley
a screw
a wedge
What type of simple machine is used to split things apart?
screw
wheel and axle
wedge
inclined plane
What type of simple machine is used to pull a flag up to the top of a flagpole?
screw
wheel and axle
inclined plane
pulley
Pulley LabA fixed pulleyB movable pulleyC double pulley (end in top)D double pulley (end in bottom)
A. fixed pulley B. movable pulley
C. double pulley (end in top) D. double pulley (end in bottom)
Get out your own sheet of paper
1. Write down the force of the weight (newtons).
2. For each pulley system write down the NEW force of the weight.
• Pull the string exactly 20 cm.
• Write down the distance (cm) that the weight moved.
• Calculate the mechanical advantage.
Force of the weight ONLY.
Hook onBottomdude !
DO THIS FIRST!
BIG Teeth=16small Teeth =8
16:82:1
So, the small gear spins TWICE AS FAST
as the big gear.
calculating mechanical Advantage
A 200 pound man lifts a rock weighing 800 pounds by standing on the end of a lever. How much mechanical advantage did the lever provide ? M.A. = 800 Kg/200 Kg = 4
If you wuz ‘n aMerry-go-round & yuz let go,Which wayz wud yu go?
Centripetal force The inward force on a spinning object,that stops it from going in a straight line.
Perpendicular
Centripetal force
Centripetal force sen tripit ulThe inward force on a Spinning object.
Centripetal force The inward force on a Spinning object.
Satellites stay in place as they orbit because of . . .
the repeated firing of rocket boosters.
the gravitational pull of Earth.
a narrow path through the vacuum of space.
solar panels generating energy to hold them in place
The End
Produced by Jake Israel
Directed by Jake Israel
Original Story by Jake Israel
Screenplay Jake Israel
Engineer Jake Israel
Photo enhancement Jake Israel
Casting Jake Israel
Editor Jake Israel
Custom animation Jake Israel
Location manager Jake Israel
Special Effects Jake Israel
Field research Jake Israel
© 2009 All rights reserved.
This powerpoint was kindly donated to www.worldofteaching.com
http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.
top related