A rocket is fired from the earth towards the sun. At what distance from the earth’s centre is the gravitational force on the rocket zero ? Mass of the sun = `2xxl0^30 kg`, mass of the earth = `6xxl0^24 kg`. Neglect the effect of other planets etc. (orbital radius = `1.5 xx 10^11 m`).

A satellite orbits the earth at a height of 400 km above the surface. How much energy must be expended to rocket the satellite out of the earth’s gravitational influence? Mass of the satellite = 200 kg, mass of the earth = 6.0xxl0^24 kg , radius of the earth = 6.4 xx 10^6 m , G = 6.67 xx 10^11 N m^2kg^2 .

Calculate the force of gravitation between the earth and the sun, given the mass of earth = 6xx 10^24 kg and of the sun = 2 xx10^30 kg . Average distance between the two is 1.5xx 10^10m .

A rocket is fired vertically with a speed of 5 km s^-1 from the earth’s surface. How far from the earth does the rocket go before returning to the earth ? Mass of the earth = 6.0 xx 10^24 kg , mean radius of the earth = 6.4 xx 10^6 m , G = 6.67 xx 10^-11 N m^2kg^-2 .

What is magnitude of gravitational force between the earth and a 1 kg object on its surface ? Take mass of earth to be 6 xx 10^24 kg and radius of the earth is 6.4 xx 10^6 m.G =6.67 xx10^-11nm^2kg^-2 .