Forces and Acceleration
The resultant force
An object may have several different forces acting on it, which can have different strengths and directions. But they can be added together to give the resultant force. This is a single force that has the same effect on the object as all the individual forces acting together.
When all the forces are balanced, the resultant force is zero. In this case:
•a stationary object remains stationary
•a moving object keeps on moving at the same speed in the same direction
When all the forces are not balanced, the resultant force is not zero. In this case:
•A stationary object begins to move in the direction of the resultant force.
•A moving object speeds up, slows down or changes direction depending on the direction of the resultant force.