What Are Forces?

Forces change the speed, shape and direction of almost everything.

Whenever you push or pull, that can be described as a force. Forces take place all around us. Even though they are invisible, we can still see their effects in the environment. As you can see from the image below, the water is falling out the bucket because there is a force acting upon it. That force is gravity (which pulls the water, out the bucket, down towards the ground. Forces change the speed and direction of movement.

If gravity was not present…

How exactly do we measure force?

We measure force in newtons (N). For example, the force exerted on the spring can be 10 newtons (N). The greater the force. the more the string stretches, so we can measure the force by measuring the stretch.

The image above shows a force meter (otherwise called a newton meter). When an object is attached to the hook, the spring stretches. So, the heavier the object is, the longer the spring will stretch, which will provide a bigger reading.

Force is measured in newtons (N).

Forces Can Be Described as a Push or a Pull

When force is applied it can alter the object’s direction of movement, speed and shape. This concept applies to contact forces (where an object must touch another object to exert a force).

  • For example, when a door is pushed open, a force is applied which causes the door to open.

A non-contact force is a force that acts on an object without physically touching it.

Examples of non-contact forces

  • Magnetic forces
  • Gravitational forces
  • Electrostatic forces (forces that electric charges exert on each other)
  • Nuclear forces