When a body is taken from the equator to the poles, its weight

The acceleration due to gravity about the earth's surface would be half of its value on the surface of the earth at an altitude of ……… $mile$. ($R = 4000$ mile)

A research satellite of mass $200 \,kg$ circles the earth in an orbit of average radius $3\,R/2$ where $ R$ is the radius of the earth. Assuming the gravitational pull on a mass of $1 \,kg$ on the earth’s surface to be $10 \,N$, the pull on the satellite will be …….. $N$. 

A weight is suspended from the ceiling of a lift by a spring balance. When the lift is stationary the spring balance reads $W$. If the lift suddenly falls freely under gravity, the reading on the spring balance will be

If density of earth increased $4 $ times and its radius become half of what it is, our weight will