Force and Acceleration

An object needs a force to start moving. - If the resultant force on a stationary object is 0, the object will remain stationary. 

No resultant force = no change in velocity. - if there is no resultant force on a moving object, it will just carry on moving at the same velocity. 

A resultant force = acceleration. - if there is a non-resultant force, then the object will accelerate in the direction of force.

Acceleration can take 5 different forms...starting, stopping,, speeding up, slowing down and changing direction 

On a force diagram, the arrows will be unequal. 

F = m x a          Resultant force, N = mass, kg x acceleration, m/s(2) 

Reaction forces are equal and opposite - when 2 objects interact, the forces rhey exert on each other are equal and opposite....

if you push something, it push back against you, just as hard. As soon as you stop pushing, so does the object.