Eni Ballauri
9A
March 2nd, 2007
Physics
Friction
‘Friction is the force that resists the motion of one surface relative to another with which it is in contact.’[1] Friction has three main kinds. Firstly, the sliding or kinetic friction, which is produced by sliding two surfaces across each other [2]. A good example is when we walk. Secondly, the rolling friction, which is resistance produced when a rolling body moves over a surface [2]. For instance, a bicycle moving in the street. Thirdly, the fluid friction or viscosity is the friction between fluids or a fluid and a solid. [2] An example for fluid friction is the boat moving in the water.
Without friction our life would definitely change. For instance, if there was not any friction between the lead of the pencil and the paper, we would not be able to write. Friction makes the wheels of a locomotive grip the rails of the track. Also, friction happens between the tyres of the car or bicycle and the road. Another example of friction that we face everyday is when we walk. There is friction between our shoes and the pavement. If there was no friction we would slide on the pavement. That’s why it is easily to slide on ice. Without friction life would be very difficult. None of the above we can do without friction. According to the first law of Newton, if there is no force on something, if still, it will say still, and if moving, it will continue moving in a straight line with a steady speed. [3] Friction is a force, and without friction we would stay still, or we would move in a straight line with the same velocity without ever stopping.
