Friction is usually called necessary evil. It means it is essential in the life and we cannot do any work without it.
Advantage of friction:-
a. Keeps the object at position :- by friction, the object can be placed at position and shaped.
b. Helps to move:- Friction forces help to move the object Ex: running or walking. With friction of feet/ shoes on the surface, helps to speed.
c. Frictional force helps to move the object in the speed. For Example :- Spikes are used by the athletes to run fast.
d. Hold or grip an object:- With the help of friction the ridges of skin of our fingers and palm enable us to grab hold objects. For example- In badminton the players use grip to hold it.
e. Produce heat:- The law of conservation of energy states that the amount of energy remain constant. Thus, the energy that is due to friction in trying to move the object is really convert into heat energy.
Disadvantages of friction:-
a. Wear and tear of object:- due to friction, there is wear and tear of object. Lubrication is used to allow the parts to move easier, moreover, prevents wear and tear.
b. Wastage of Energy:- Excess of friction means extra energy, thus energy is being wasted.
c. Slow down the speed:- In the roller sketting, Rolling shoes and smooth surface are used to minimize friction.
d. Makes movement difficult :- Friction can make the job more difficult when one has to move the other object. Excess friction can make it difficult to slide a box across the floor, walk through deep snow.
