5-Effects of forces

There are many different types of force. These include pushes, pulls, twists and stretches.
If you apply a force to an object it may:
• Make it start to move
• Make it move faster
• Slow it down
• Make it stop
• Change the direction in which it is moving
• Change its shape

Sometimes it is not necessary to be in contact with an object in order to apply a force to it.
The steel nails in figure are lifted by a force. This attractive force exists between magnets and magnetic materials such as iron and steel.
The bungee jumper in figure has just jumped out of the basket and is feeling the force of gravity pulling him downwards. The common name given to this force is weight.
There are gravitational forces between all objects, but they are often very weak. They are only noticeable when one or both of them are massive, such as a planet, moon or star. It is gravitational forces of attraction that hold the Moon in orbit around the Earth and hold the planets in orbit around the Sun.