Forces

Anything that pushes or pulls an object is called a force. A breath of wind, a car engine, a magnet and an elastic band are all examples of things that can produce a force. A force...

Forces A-Z

Friction

When two objects which are touching try to move past each other, they rub against each other. This produces a force called friction which tries to stop the movement. If the...

Gravity

The Universe is made of matter. Matter is held together and moved by forces. One of the basic or fundamental forces is the gravitational force—also more simply known as gravity...

Machines

A machine uses physical efforts, forces and work to get a job done. It can be as complicated as a jet engine or a combine harvester to gather crops. Yet it can be as simple as a...

Motion

Motion is any kind of movement. Motion is caused by forces. A still or stationary object does not move unless a force acts on it to start it going. Once it is moving it carries on...

Why do ships float?

If you dropped a small stone into the water, it would sink immediately. But if a block of steel weighing thousands of tonnes were made into a ship, it would float. Any object...

How does an airliner fly?

How does an airliner, weighing 350,000 kilos (nearly 400 tons), lift off from the ground and fly through the air? It relies on its engines to drive it forward at high speed and its...