Force and pressure

Question

2. Of the following statements, choose the correct combination. (a)Grease is used to reduce friction in bicycle chain (b)Ball bearings are used to reduce friction in a fan (c)Oil can be used to increase friction in a car engine (d)Talc can be used to reduce friction when an object is sliding on a surface (A)a ,b ,d (B)a ,c ,d (C)b ,c ,d (D)a ,b ,c

Answer 1

Answer: A, B, D
Friction is reduced by using oil, grease, ball bearings and talc.
Because by the use of these things, the surface becomes smooth and therefore it helps in reducing the force of friction.