Question

A bucket is whirled in a vertical circle with a string attached to it. The water in the bucket does not fall down even when the bucket is inverted at the top of its path. We can say that in this position.

• A. $mg=\frac{m{v}^2}{r}$
• B. mg is greater than $\frac{m{v}^2}{r}$
• C. mg is not greater than $\frac{m{v}^2}{r}$
• D. mg is not less than $\frac{m{v}^2}{r}$

Answer 1

Answer: (A), (C)

The correct options are
A $mg=\frac{m{v}^2}{r}$
C mg is not greater than $\frac{m{v}^2}{r}$

When the bucket is at the top of its path, the forces acting on the water are gravity and centripetal force. Since, the water does not fall down. Therefore, centripetal force is greater than the force of gravity.

Therefore, $\frac{m{V}^2}{R}\ge mg$