if the angular speed of earth becomes 17times its present value what will be the 1.effect on a body on the equator of earth? it will be

A. Heavier than present value
B.lighter than present value
C.weightless
And also what is the reason?

2.a girl sitting on a swing stands up. What will be the effect on the periodic time of the swing?

To determine the effects on a body on the equator if the angular speed of the Earth becomes 17 times its present value, we need to understand the concepts of centrifugal force and gravitational force.

1. Effect on a body on the equator:
As the angular speed of the Earth increases, the centrifugal force acting on a body on the equator will also increase. However, the gravitational force acting on the body, which is dependent on the mass of the Earth, remains unchanged.

Since the centrifugal force increases while the gravitational force remains constant, the net effective force on the body decreases. As a result, the body will become lighter than its present value.

Therefore, the correct answer is B. Lighter than present value.

The reason for this is that the centrifugal force acts outward, away from the center of rotation (which is the axis of the Earth). This force opposes the inward gravitational force, making the effective force on the body smaller.

2. Effect on the periodic time of the swing:
When a girl sitting on a swing stands up, the length of the swing arc (the distance between the girl and the pivot point) increases. By increasing the length of the swing arc, the period or the time taken to complete one swing back and forth will also increase.

Standing up on the swing essentially increases the distance traveled by the girl during each swing. Since the period of a simple pendulum (such as a swing) is dependent on the length of the pendulum, increasing the length will result in an increase in the period of the swing.

Therefore, the effect of the girl standing up on the swing is that the periodic time of the swing will increase.