The weight of a body on the surface of the earth is $100\,N$. The gravitational force on it when taken at a height, from the surface of earth, equal to onefourth the radius of the earth is $..........\,N$

If the angular velocity of earth's spin is increased such that the bodies at the equator start floating, the duration of the day would be approximately ........ minutes

(Take : $g =10 \,ms ^{-2},$ the radius of earth, $R =6400 \times 10^{3}\, m ,$ Take $\left.\pi=3.14\right)$

The mass of the earth is $81$ times that of the moon and the radius of the earth is $3.5$ times that of the moon. The ratio of the acceleration due to gravity at the surface of the moon to that at the surface of the earth is

The ratio of gravitational acceleration at height $3R$ to that at height $4R$ from the surface of the earth is : (where $R$ is the radius of the earth)

A simple pendulum has a time period ${T_1}$ when on the earth’s surface and ${T_2}$ when taken to a height $R$ above the earth’s surface, where $R$ is the radius of the earth. The value of ${T_2}/{T_1}$ is

As we go from the equator to the poles, the value of $g$