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Terms:

• External force
• Impulse
• Internal Force
• Momentum
• Momentum Conservation
• Collision
• Elastic Collision
• Angular Momentum
• Angular velocity
• Lever Arm
• Precession
• Rotational Inertia
• Rotational Motion
• Torque
• Uniform Circular Motion

Concepts

Motion and Speed

• Motion is defined as a change in position, so what is speed? How fast that change takes place. Or, the time it takes to cahnge postion.
• When speed has direction it then has velocity.
• Any change in velocity is called acceleration, whether it be fowards or backwards, or even sideways. To calculate acceleration we simply use the equation a= Æv/t or change in velocity over time.
• Most times when speak of average speed or velocity rather than instantenous speed.
• to calculate speed we use the equation v=d/t.

Newton's laws

• 1st - inertia an object wants to keep doing what it is doing unless something acts upon it to change the forces
• 2nd F= ma
• 3rd action / reaction

Force is a vector

• having both magnitude and direction
• total force is zero or balanced unless something is moving
• net force is the sum of all the forces in a situation

Tension

• weighing of an object with a spring scale

Frictional Forces

• variable dependant on velocity and mass
• the force that resists motion

Air friction also called air resistance

• terminal velocity the balanced force between air molecule's friction and gravity

Momentum

• is realted to F=ma the equation is p=mv which means something that is massive (big) that is moving fast has alot of momentum - think about stopping a train!!
• momentum can be transfered from one item to another, such as in a cue ball in pool
• a collision is when two objects hit one another and exchange momentum