If the radius of the Earth decreases without any change in its mass,will the value of $g$ on its surface increase or decrease?

$A$ hole is drilled halfway to the center of the Earth. $A$ body weighs $300 \ N$ on the surface of the Earth. How much will it weigh at the bottom of the hole (in $N$)?

Two planets have radii $r_1$ and $r_2$ and their densities are $p_1$ and $p_2$ respectively. The ratio of the acceleration due to gravity on their surfaces will be:

Derive the equation for the variation of $g$ due to height from the surface of the Earth.

The angular speed of rotation of the Earth about its axis,at which the weight of a man standing on the equator becomes half of his weight at the poles,is given by:

The maximum vertical distance through which a fully dressed astronaut can jump on the earth is $0.5\, m$. If the mean density of the moon is two-thirds that of the earth and the radius is one-quarter that of the earth,what is the maximum vertical distance through which he can jump on the moon and the ratio of the duration of the jump on the moon to that on the earth?