MOTIONMOTIONLesson 1: What Factors Affect Lesson 1: What Factors Affect

Motion?Motion?

Lesson 2: What Are the Laws of Lesson 2: What Are the Laws of Motion?Motion?

Lesson 1: What Factors Affect Lesson 1: What Factors Affect Motion?Motion?

How can you tell is How can you tell is something is something is moving?moving?

You must compare it You must compare it to something the is to something the is standing still.standing still.

This is called a This is called a frame frame of reference.of reference.

You look at both You look at both objects inside a objects inside a “frame.”“frame.”

Lesson 1Lesson 1

How can you define motion?How can you define motion? An object is in motion when it changes An object is in motion when it changes

position.position. Position is an object’s location in space.Position is an object’s location in space. We use words like We use words like east, behind, left, righteast, behind, left, right, ,

and and aboveabove to describe motion. to describe motion.

Lesson 1Lesson 1 Forces can make Forces can make

objects change objects change position.position.

All forces are pushes All forces are pushes or pulls.or pulls.

Gravity is a force Gravity is a force that pulls objects that pulls objects toward each other.toward each other.

The pull of the The pull of the Earth’s gravity Earth’s gravity keeps your chair on keeps your chair on the floor.the floor.

Lesson 1Lesson 1

Friction is a force Friction is a force that opposes motion.that opposes motion.

Is slows objects Is slows objects down and prevents down and prevents them from motion.them from motion.

The smoother the The smoother the surface is between surface is between the two objects, the the two objects, the less friction there is.less friction there is.

Not enough friction Not enough friction here. Too smooth of a here. Too smooth of a surface.surface.

Lesson 1Lesson 1

Forces work together to affect the way an object Forces work together to affect the way an object moves.moves.

An airplane in flight is pulled to the ground by gravity.An airplane in flight is pulled to the ground by gravity. But a force called But a force called lift lift pushes it up.pushes it up. DragDrag from the air slows the plane. from the air slows the plane. But But thrustthrust from the engines pushes the plane forward. from the engines pushes the plane forward.

Lesson 1Lesson 1 Some things move fast, Some things move fast,

some things move slow.some things move slow. How can you describe How can you describe

how fast something is how fast something is moving?moving?

The measurement is The measurement is called called speedspeed..

Speed is the distance Speed is the distance an objects travels in a an objects travels in a certain amount of time.certain amount of time.

““Thirty miles per hour” Thirty miles per hour” is an example of speed.is an example of speed.

Lesson 1Lesson 1 Sometimes you also need Sometimes you also need

to know the direction an to know the direction an object is going.object is going.

Velocity measures an Velocity measures an object’s speed in a object’s speed in a certain direction.certain direction.

One car’s velocity may One car’s velocity may be 50 miles per hour be 50 miles per hour east. Another car’s east. Another car’s velocity may be 50 miles velocity may be 50 miles per hour west.per hour west.

The two cars have the The two cars have the same speed, but same speed, but different velocities.different velocities.

Lesson 1Lesson 1 Acceleration is the Acceleration is the

rate at which velocity rate at which velocity changes. changes.

Some car Some car advertisements talk advertisements talk about acceleration. about acceleration. The ad might say, The ad might say, “Zero to sixty in five “Zero to sixty in five seconds.”seconds.”

The advertisement is The advertisement is talking about talking about acceleration.acceleration.

Lesson 1Lesson 1 Momentum Momentum describes describes

how easy or hard it is how easy or hard it is to stop a moving object.to stop a moving object.

Momentum depends on Momentum depends on how much mass the how much mass the object has.object has.

It also depends on the It also depends on the object’s velocity.object’s velocity.

The more momentum The more momentum an object has, the an object has, the harder it will be to stop harder it will be to stop that object with a force. that object with a force.

Lesson 2: What Are the Laws of Lesson 2: What Are the Laws of Motion?Motion?

Isaac Newton Isaac Newton described how things described how things move using three move using three Laws of Motion.Laws of Motion.

Law ONE: InertiaLaw ONE: Inertia Law TWO: Law TWO:

Acceleration depends Acceleration depends on force/mass.on force/mass.

Law THREE: For Law THREE: For every forceful action, every forceful action, there is an equal and there is an equal and opposite reaction.opposite reaction.

Lesson 2Lesson 2 Law One:Law One: Moving objects tend to keep moving.Moving objects tend to keep moving. Objects that are not moving, tend to stay Objects that are not moving, tend to stay

still.still. This is inertia.This is inertia. For example: If you kick a ball, the ball For example: If you kick a ball, the ball

will move. Kicking the ball overcomes the will move. Kicking the ball overcomes the inertia that keeps the ball at rest.inertia that keeps the ball at rest.

Lesson 2Lesson 2 Law TWO:Law TWO: If you kick a ball gently, If you kick a ball gently,

it will move slowly.it will move slowly. If you kick a ball hard, it If you kick a ball hard, it

will move faster.will move faster. Newton’s 2Newton’s 2ndnd law says law says

than an object’s than an object’s acceleration depends on acceleration depends on the force you apply to it.the force you apply to it.

The more force you The more force you apply, the greater the apply, the greater the acceleration.acceleration.

Lesson 2Lesson 2 Law THREE:Law THREE: The third law says The third law says

that every action that every action force will have an force will have an equal and opposite equal and opposite reaction force.reaction force.

When you push a When you push a heavy box, you heavy box, you apply an action apply an action force. The box force. The box pushes back with a pushes back with a reaction force.reaction force.

Lesson 2Lesson 2 You have probably seen You have probably seen

pictures of astronauts pictures of astronauts floating in their space floating in their space shuttle.shuttle.

It looks as though there is It looks as though there is no gravity in space, but no gravity in space, but this is not true.this is not true.

There is gravity, but in There is gravity, but in space, gravity is balanced space, gravity is balanced by inertia.by inertia.

The space shuttle moves The space shuttle moves fast enough so gravity fast enough so gravity does not make it fall to does not make it fall to Earth.Earth.