NDA || Physics || mechanics || Kinematics || Quiz 2020

A body of mass 10 kg was taken to 2 points. First at a point 10 km above the surface of the earth and second to a point 10 km below the surface of the earth. Find the ratio of weights of the first point to the second. (mean radius of earth = 6400 km)

Assume to save a bit of rocket fuel, and a space organization decides to launch space vehicles from some height in the atmosphere such that now the fuel required is ¾ of the fuel when it was launched from the surface. Find the height from which the vehicles should be launched. (radius of earth = 6400 km)

Find the gravitational kinetic energy of a satellite of mass 10³ kg orbiting the earth at a height of 800 km. Given the mass of earth is 6 × 10²⁴ kg , radius of the earth is 6400 km and universal gravitational constant G = 6.67 × 10^-11 N m² kg^-2. ( 1 GJ = 10⁹ J)

In a solar system, 2 planets are revolving at a distance of 10¹⁸ m and 10¹⁰ m from the sun in circular orbits. Find the ratio of their orbital speeds.

Find the angular momentum of a satellite of mass 10³ kg revolving around the earth at the height of 37,700 km from the surface of the earth. Given universal gravitational constant G = 6.67 × 10^-11 N m² kg^-2, the radius of earth 6400 km and mass of the earth 6 × 10²⁴ kg.