If earth rotates faster than its present speed the weight of an object will.

1) increases at the equator but remain unchanged of the poles.

2) Decreases at the equator but remain unchanged at poles.

3) Remain unchanged at the equator but decreases at poles.

4) Remain unchanged at the equator but increases at the poles.

Answer: 2) Decreases at the equator but remain unchanged at poles.

Solution:

If the earth rotates faster than the present speed, the centrifugal force at the equator will increase, thus increasing the weight of the body. Since the poles are along the axis of rotation, the centrifugal force at the poles will be zero.