Question

An object slides without friction in a bowl shaped like a hemisphere. It is released from rest at one edge of the bowl, slides through the bottom, and then slides up the other side before stopping right on the edge of the bowl. During which part of this process is the power being delivered by the gravitational force at its greatest? Note that we want the greatest positive power.

Answer 1

Options:

a. At the beginning.

b. When the object is at the bottom of the bowl.

c. At the end.

d. Sometime between the start and when the object reaches the bottom of the bowl.

e. Sometime between when the object reaches the bottom of the bowl and the end.

Answer:  D. Sometime between the start and when the object reaches the bottom of the bowl.

Explanation: When an object is at the top before it starts to slide the power is zero, because there is no velocity, as it starts to slide to the bottom the power starts to increase,the angle as it slides continues to be increasingly  bad before it reaches the bottom of the bowl.

The greatest positive power will be somewhere between the start and when the object reaches the bottom of the bowl.