# Physics 2 - Forces and Acceleration

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• Created by: Sash
• Created on: 21-05-13 11:32

Forces and Acceleration

An object needs a force to start moving. Things don't just start moving on their own, there has to be a resultant force to get it started. If the resultant force on a stationary object is zero, the objct will remain stationary.

No resultant force means no change in velocity. If there is no resultant force on a moving object it will just cary on moving at the same velocity.

• When a train or a car or a bus or anything else that is moving at a constant velocity then the forces on it must all be balanced.
• Things DO NOT need a constant overall force to keep them moving
• To keep going at a steady soeedm there must be zero resultant force

A resultant force means acceleration. If there is a non-zero resultant force, then the object will accelerate in the direction of the force,

• A non-zero resultant force will always produce acceleration
• This "acceleration" can take five forms:

1) Starting

2) Stopping

3) Speeding Up

4) Slowing Down