When a body is taken from pole to the equator its weight

The weight of a body on the surface of the earth is $63\, N$. What is the gravitational force on it due to the earth at a height equal to half the radius of the earth ? (in $N$)

Radius of the earth is $R$. If a body is taken to a height $3R$ from the surface of the earth than change in potential energy will be

The escape velocity of a body from earth's surface is $v_e$ . The escape velocity of the same body from a height equal to $R$ from the earth's surface will be

The kinetic energy needed to project a body of mass $m$ from the earth's surface (radius $R$) to infinity is