Types of friction
i)Static friction
ii)Dynamic friction
a)Sliding friction
b)Rolling friction Friction : advantageous or disadvantageous with example. Friction is usually called a necessary evil. It means that it is essential in games and sports. Without friction we cannot give a better performance for example athletes use spikes and football players use studs to have appropriate friction, without friction they are unable to run fast. Even gymnasts use lime powder on their palms to perform on horizontal bar, Uneven bar and roman rings. On the other hand friction is disadvantageous in some games. In cycling there should not be more friction between road and the tyres of the cycle. If there is more friction there will be more wastage of energy of the rider and leads to damage of equipments.