Question

Water in a bucket is whirled in a vertical circle with string attached to it. The water does no fall down even when the bucket is inverted at the top of its path. We conclude that in this position
(a) mg=mv2r
(b) mg is greater than mv2r
(c) mg is not greater than mv2r
(d) mg is not less than mv2r.

Answer 1

We can conclude that (c) mg is not greater than mv²/r

Explanation:

• When the bucket is inverted, the gravitational force acts on the water and the water is supposed to move downward.
• But it does not, this is because the inertia of the water makes the water to be at the rest position for sometimes.
• If the inverted position is prolonged the water falls, but it doesn't in faster movement.
• From this, mg (gravitation force) < mv²/r (centripetal force)
• Thus, the water doesn't fall.

Answer 2

mg is not greater than mv2r.

Explanation

• The direction of mg at the top of the route is downwards vertically and for centrifugal force $\left(\frac{m v^{2}}{r}\right)$, The path is uphill vertically.
• If the downward force is not greater vertically, otherwise water will not drop.

Centrifugal force:- A force that occurs from the inertia of the body that tends to act on a body traveling in a circular direction, and is guided away from the center around which the body travels.