Question

Which of the following statements is incorrect?

• A. Friction acts on a ball rolling along the ground.
• B. Friction acts on a boat moving on water.
• C. Friction acts on a bicycle moving on a smooth road.
• D. Friction does not act on a ball moving through air.

Answer 1

The correct option is D

Friction does not act on a ball moving through air.

The explanation for incorrect options:

In the case of options A, B, and C:

1. Friction is caused by irregularities on the two surfaces that come into contact.
2. As a result, when one object moves over another, the surface irregularities become entangled, causing friction.
3. The greater the roughness, the more irregularities and the greater the friction.
4. To avoid creaking sounds from doors, we lubricate the door hinges, which results in a smooth door hinge operation.
5. As fluid friction, friction acts on a moving body in the air.

So, all (A),(B), and (C) are correct statements that means, these options are incorrect

The explanation for the correct option:

In the case of option D:

1. The force that prevents fluid from flowing freely is known as fluid friction.
2. The fluid acts as a barrier between the two surfaces in this condition.
3. When both surfaces have a high level of resistance, it is said to be highly viscous, and it is also called greasy.
4. As fluid friction, friction acts on a moving body in the air.
5. So, option (D) has an incorrect statement.

Hence, option (D) is the correct answer.