NCERT Solutions for Class 8 Term_policy Chapter 12 Friction

Friction opposes the ____________ between the surfaces in contact with each other.

Friction depends on the ____________ of surfaces.

Friction produces ____________ .

Sprinkling of powder on the carrom board ____________ friction.

Sliding friction is ____________ than the static friction.

Four children were asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. Their arrangement are given below. Choose the correct arrangement:

• Rolling, static, sliding

• Rolling, sliding, static

• Static, sliding, rolling

• Sliding, static, rolling

Alida runs her toy car on dry marble floor, wet marble floor, newspaper and towel spread on the floor. The force of friction acting on the car on different surfaces in increasing order will be :

• Wet marble floor, dry marble floor, newspaper and towel.

• Newspaper, towel, dry marble floor, wet marble floor.

• Towel, newspaper, dry marble floor, wet marble floor.

• Wet marble floor, dry marble floor, towel, newspaper.

Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show the direction of frictional force acting on it.

You spill a bucket of soapy water on a marble floor accidently. Would it make easier or more difficult for you to walk on the floor? Why?

Explain why sportsmen use shoes with spikes.