Question

The picture shows a bucket being whirled around in a circle (neglect gravity). Think about the correlation between this action and the motion of the moon around the earth. Then pick out the incorrect statement.

• A. The bucket is in circular motion similar to the motion of the moon.
• B. The force exerted by the thread on the bucket is replaced by the gravitational force in case of the moon.
• C. If there is no string, the bucket will not whirl. Similarly, if there is no gravitational force, there will be no moon revolving around the earth.
• D. The speed with which the bucket moves can never be constant.

Answer 1

The correct option is D

The speed with which the bucket moves can never be constant.

Centripetal force makes an object to rotate in a circular motion. Here, the whirling of the bucket with the help of a string is similar to the revolving of the moon around the earth. The centripetal force in case of the bucket is the tension (The pull of string on the bucket).
Similarly, the gravitational force between the moon and the earth act as the centripetal force for its rotation. By all means the bucket can revolve with a constant speed similar to the moon.