Suppose the earth increases its speed of rotation. At what new time period will the weight of a body on the equator becomes zero ?

Q: Suppose the earth increases its speed of rotation. At what new time period will the weight of a body on the equator becomes zero ? (Given, g = 10 ms-2 and radius of the earth, R = 6400 km)

(a) 9/4π

(b) 4/9π

(c) 9/5π

(d) 5/9π

Ans: (b)