# Forces

Source: https://projectgcse.co.uk/physics/forces_motion/forces

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- Forces are usually a push or a pull.
- Forces are measured using a newtonmeter and the unit of force is Newtons.
- Forces work in pairs - as you push down on a table the table pushes up with equal force.
- When there is no change in velocity or shape of an object then the forces are balanced e.g. book on table
- When there is a change in velocity or shape of an object then the forces are not balanced e.g. person falling through ice.
- An example of a force is gravitational force. To work out the weight of an object (with gravity working on it) you use the following formula:
- Weight (N) = mass (kg) x gravitational force (N/kg)
- The main formula to use to work out forces is:
- Force (N) = mass (kg) x acceleration (m/s/s)
- OR F=ma