speed

the distance traveled divided by the time

(s=d/t)

(s=d/t)

average speed

the total distance traveled divided by the total time taken

instantaneous speed

the speed of an object at one moment in time

acceleration

change in velocity divided by time taken for the change to take place

positive acceleration

speed up

negative acceleration

slow down

velocity

speed and direction of a moving object

inertia

tendency of an object to resist a change in it's motion

momentum

a measure of how hard it is to stop a moving object; dependent on it's mass and velocity

law of conservation of momentum

the total momentum of objects that collide with each other is the same before and after the collision

collision

when two or more objects hit each other

motion

a change in position

relative motion

a change in position of one object compared to the position of another

distance

how far an object moves

displacement

the distance and direction an object moves relative to it's starting point