Physics GCSE: Forces, Moments and Pressure
What can forces do?
A force can do one of four things to an object: - Make it speed up - accelerate.
- Make it slow down - decelerate.
- Change its direction.
- Change its shape.
If something is doing one of these four things there must be a
net force acting upon it.
(
Note: Other names for a
net force are an
unbalanced force or a
resultant force.)
What do we mean by a 'net' force?
Well, forces do not add up like normal numbers - you must take their direction into account as well. For example, if you were teetering on the edge of a cliff and someone applied a force to you, you would probably like the force applied in a certain direction.
It is easy to add up forces, just look at these three examples:
The unit we measure force in is the Newton, named after Sir Isaac Newton, which leads us onto Newton's first law.
