We sometimes call this RELATIVE motion.

We have to see something move in relation to something else – we need a FRAME OF REFERENCE

It’s like a tug-o-war

When both sides are evenly matched, neither one wins, and there is no mevement

If one side starts to overcome the other, the center of the rope

moves toward the stronger side

We have created motion with unbalanced force

Law #1

Objects that are in motion will stay in motion

Objects at rest will stay at rest

Unless a force acts on them

Law #2

For Every Action, there is an equal and opposite reaction

“You push on the floor as hard as the floor pushes back on you.”

Law #3

Force = Mass x acceleration

The bigger you are, the harder you hit

The faster you run, the harder you hit

Acceleration is an increase or decrease in speed.

Sometimes we say that acceleration is a change in speed.

No, it’s not Lightning McQueen

Speed is how far you went divided by how look it took to get there

Speed = distance/time

Gravity accelerates things toward the center of the earth

The higher above the ground something is, the longer it has to fall, and the faster it will be going when it hits the ground.

When something is way up high, it has the POTENTIAL to fall a long distance, and get going really fast, so we say it has POTENTIAL ENERGY

When something finally does fall off, we say that it has KINETIC ENERGY, or the energy of MOTION.

Remember those unbalanced forces?

When the force of friction slowing down a skiier is not equal to the force of gravity accelerating him, motion happens!

Friction always acts in the direction opposite of motion.

When there is little friction, funny things happen