Forces

                                                                         Forces

 Our life is full of forces. We cannot see them but we can see how they affect things. All sports involve forces. You can use a force when you run or when you ride a bike. 

When you take part in certain sports you need special equipment to protect you from some forces or help you to produce bigger forces. Many sports would not be possible without modern technology. 

For many forces, the thing provided the force needs to touch an object before the force can affect it. These are called contact forces. For example when you throw a ball, you need to touch it to exert a force on it. When you need to go down a steep hill on a bicycle, the brakes need to touch the wheel to produce friction to slow you down . Contact forces include friction, air resistance, water resistance and  up thrust (the force that makes things float).

Some forces can affect an object from a distance. these are call non-contact forces. Gravity is a force that pulls objects down wards. Static electricity can attract things. For example a man is climbing the side of a ship using magnets. Magnets have magnetism which attracs objects made from iron and some other metals.