FORCE, ENERGY & MOTION

SOL 4.2

SPEED describes how fast

an object is moving.

ENERGY may exist in two states:

potential or kinetic.

Potential energy is stored energy.

Kinetic energy is the energy of motion.

Potential energy is stored energy.

What are some other examples of potential energy?

*A baseball pitcher right before he throws the ball.

*A roller coaster at the top of a tall hill.

Kinetic energy is energy of motion.

What are some other examples of kinetic energy?

*A baseball pitcher as he throws the ball.

*A roller coaster going down the hill.

Kinetic energy is energy of motion.

*When an object is in motion, it changes position by moving in a direction:

*ALL ALL moving objects have kinetic energy.

A forceforce is any push or pull

that causes an object to: • Forces transfer energy.

•When you throw a ball, the force of your arm pushes the ball into the air.

• Energy is transferred from your arm to the ball.

Without force, an object at rest will

stay at rest!

The pull of gravity is a force that might set an object (or a skier) in motion. The pull or push of a magnet is another force that can move objects. The force you exert with your legs or arms can set a ball in motion.

Unless acted on by a force, an object in motion will stay in

motion!

•The force stopping the object's motion might be an obvious one - the ground!

An object will continue to move until a force slows or stops it.

The greater the force, the greater the change

in motion.

The more massive an object, the less effect a force will have on an

object.

For example, it's easier to push a light plastic ball than a more massive boulder. It's also harder to stop a boulder when it is rolling down a slope.

FRICTION is the resistance to motion

created by two objects moving against each

other.

FRICTION creates

.

Rub your hands together!

the sled and the snow, for instance

The skier is standing at the top of the mountain. Is the picture meant to show potential or kinetic energy?

 

the red vase on the second shelf

 the blue vase on the top shelf

 

 

the white box on the bottom shelf

Which object on the shelf has the

greatest potential energy?

These passenger are just starting their descent. What's happening?                            

potential energy is changing to kinetic energy