Watch the video to learn more about the 4 types of Forces: Gravitational Force, Frictional Force, Magnetic Force and Elastic Spring Force.
Key concepts of Forces:
A force is a push or a pull.
A force can cause things to change its speed, direction, shape or size.
Gravity is the force of attraction between objects.
Gravity depends on the mass of the objects and the distance between them.
Earth's gravitational force acts on all objects that are near it all the time, even when they are not moving.
Friction is a force that opposes motion.
Friction produces heat energy.
Friction can be useful (provides a grip to prevent slipping or skidding). It can also be a problem (wears out parts or over heat).
Elastic spring force
Elastic spring force occurs when an elastic object is stretched, bent, twisted or compressed.
When a load is hung onto a spring, the spring stretches. Extension = New length - Original length. The larger the load hanging on a spring, the greater the extension of the spring. The load and extension are proportional up till a certain point.
Take this quiz to recap what you have learnt. Aim to reach the moon!