Question

What happens to the weight of the body if the speed of rotation of earth incrases?

Answer 1

when the rotational speed of the earth increases then the body on the earth will feel some weight lose as when the speed will increase the centrifugal force will also increase that is acting on the surface of the earth thus the increase in the speed causes the weight loss of the body as the weight of the body will decrease.
so overall the increasing speed of the rotation of the earth will decrease the weight on the earth because of centrifugal force that is acting on the surface of Earth.