Question

Why can dust be removed from a carpet by shaking it, or by beating it with a stick?
A. Because of inertia of rest
B. Because of inertia of motion
C. Because of inertia of direction
D. Because of momentum

Answer 1

Hint: The property of inertia is the property of a body that causes it to tend to stay in a steady state of motion or at rest unless an external force is applied to the body. When a carpet filled with dust is beaten by a stick the carpet moves or we can say comes in motion but the dust particles remain at rest.

Complete answer:
Newton's first law of motion or law of inertia states that until and unless an external force is applied on the body, the body at rest will remain at rest and the body in motion will remain in motion. Inertia is the tendency of a body to oppose any change in its rest or in its motion.

When a carpet is shaken or beaten with a stick the material of the carpet moves in forward and backward directions. The dust particles on the carpet tend to remain at rest due to their property of inertia. Since the dust particles get separated from the carpet because they are still at rest, they fall under the force of gravity.

Hence, option A is the correct option.

Note: The mass of a body determines its inertia. The bigger the mass, the more is the inertia. As a result, it will be harder to remove tiny dirt from the carpet than bigger dirt particles, because the dust particles will have less inertia and will move with the carpet.