A pendulum clock is set to give correct time at the sea level. This clock is moved to hill station at an altitude of $2500\, m$ above the sea level. In order to keep correct time of the hill station, the length of the pendulum

The acceleration due to gravity on the surface of earth is $g$. If the diameter of earth reduces to half of its original value and mass remains constant, then acceleration due to gravity on the surface of earth would be :

If ${R}_{{E}}$ be the radius of Earth, then the ratio between the acceleration due to gravity at a depth $' {r} '$ below and a height $' r '$ above the earth surface is:

(Given : $\left.{r}<{R}_{{E}}\right)$

The acceleration due to gravity on the planet $ A $ is $9$ times the acceleration due to gravity on planet $B$. $A$ man jumps to a height of $2\,m$ on the surface of $ A$. What is the height of jump by the same person on the planet $B$..........$m$

The weight of a body at the centre of the earth is

A body has a weight $90\, kg$ on the earth's surface, the mass of the moon is $1/9$ that of the earth's mass and its radius is $1/2$ that of the earth's radius. On the moon the weight of the body is .......... $kg$