Physics Revision

• **What will happen if you crash your car into something?

Your body will resist the change in motion and, unless something else stops it first, your body will crash into the object at the same velocity that the car crashed into the object.**

• what happens to objects when you crash your car into something?

They will experience equal but opposite forces, have identical time of impact but because of different masses will experience different changes in velocity and acceleration.

• purpose of seatbelt

decrease passenger’s velocity

• Newton 2

force = mass x acceleration. The greater the mass of the object being accelerated, the greater the amount of force needed to accelerate the object. Acceleration of an object with constant mass is proportional to the net force action on it

• positive velocity

direction the object travelling is forward

• Speed

distance / time. distance an object travels per unit of time. km / h OR km hr -1

• Velocity

speed of an object in a particular direction. vector quantity ( has magnitude + direction)

• Velocity formula

Displacement / Time

• Acceleration

rate of change in velocity per unit of time. Vector quantity.

• Acceleration formula

a = v-u / t

• displacement

vector quantity - change in object’s including how far it moved and which direction p