NCERT Question 2 - Chapter 12 Class 8 - Friction

Four children were asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. Their arrangements are given below.

Choose the correct arrangement.

(a) Rolling, static, sliding

(b) Rolling, sliding, static

(c) Static, sliding, rolling

(d) Sliding, static, rolling

Answer

(c) static, sliding, rolling

Friction is the force which opposes relative motion of object.

Static fiction is the friction when we try to move an object from rest

Sliding friction is when an object slides over the surface of another object. Sliding friction is smaller than static friction because time required for interlocking between the two surfaces

is less because object is already moving

Rolling friction is when an object rolls over the surface of another object. It is easier to roll than to slide. So, rolling friction is less than sliding friction

Hence, Static Friction > Sliding Friction > Rolling Friction