Motion and Forces Review

Unit 5

Velocity

Speed• 50 Miles per hour• 25 m/s• 50 mph• 10 meters per second

Velocity• 50 miles per hour east• 25 m/s towards home• 50 mph left• 10 meters per second up

Friction

• Occurs between all things in motion and contact

• Always opposes motion• Static > Kinetic• Rolling < Sliding• Slows things down.

Unbalanced Forces

• What would the result of forces on the box below be?

Newton’s 1st Law

• The law of inertia• No change in motion will occur without an

unbalanced force.

Average Speed

• S= d/t

Inertia

• The tendency of an object to remain at rest or in motion

• Newton’s 1st Law• Depends on an objects mass but not velocity• More massive objects have more inertia

Gravity

• Fundamental force of nature• Depends on mass of objects and distance

between them.• If Gravity decreases, weight decreases• If Gravity decreases, mass remains the same

Newton’s 3rd Law

• Law of Action-Reaction• Action Force = Reaction Force• For every action there is an opposite and

equal reaction.

Newton’s 2nd Law

• Force = mass x acceleration• F=ma• If a toy car is pushed with a 5 N force and has

a mass of 10 kg what will it’s acceleration be?

Momentum

• Momentum= mass x velocity• p=mv

Effect of forces