Question

A boy rolls a rubber ball on a wooden surface. The ball travels a short distance before coming to rest. To make the same ball travel a longer distance before coming to rest, he may

• A. Spread a carpet on the wooden surface.
• B. Cover the ball with a piece of cloth
• C. Sprinkle talcum powder on the wooden surface.
• D. Sprinkle sand on the wooden surface

Answer 1

The correct option is C

Sprinkle talcum powder on the wooden surface.

Explanation for the correct option

Option (C)

1. Friction is a property of matter, which resists the motion of a body and acted opposite to motion at the point of contact between two surfaces.
2. Friction is caused due to the roughness of the contact surface and the moving body. When the ball moves on the wooden table, a frictional force will be active due to friction on the ball.
3. This frictional force prevents the motion of the ball. If we reduce the irregularities or roughness of the surface (friction), then the ball will travel a longer distance. Talcum powder is an anti-frictional matter, which can reduce friction. So, the ball will moves a longer distance.

Explanation for the incorrect options

Option A

1. Spreading a carpet on the wooden surface will increase the irregularities or roughness of the wooden surface, that's why friction will increase. So, the ball will stop after some moment.

Option B

1. Covering the ball also increases the irregularities or roughness of the wooden surface. So, the ball will stop after some moment.

Option D

1. Sprinkle sand on the wooden surface again increases the irregularities or roughness of the wooden surface. So, the ball will stop after some moment.

So, option C is correct.