Physics Gravitation

When a soap bubble is illuminated by source of white light, it appears coloured. This is due to

If the earth suddenly stop rotating, the value of ‘g’ at the equator would

Energy required to shift a body of mass m from an orbit of radius 2R to 3R is (mass of planet is M)

The radii of circular orbits of two satellites A and B of the earth, are 4R and R, respectively. If speed of satellite A is 2V, then the speed of satellite B will be

A wire can be broken by a load of 20 kg-wt. The force required to break wire of same material with twice the diameter will be

The height at which the weight of an object becomes (1/16)^th of its weight on the surface of earth is (R is radius of earth)

The radii of circular orbits of two satellites A and B of the earth, are 4R and R, respectively. If speed of satellite A is 2V, then the speed of satellite B will be

If an object is having same weight at same distance above and below the surface of earth, find its distance from surface of earth.

At a point away from planet of radius 6400 km, the gravitational potential and field are –6.4 × 10⁷ SI units and 6.4 SI units respectively. Find height of that point above surface of planet.

Mass of moon is $\frac{1}{81}$ <!-- [if gte mso 9]><xml> </xml><![endif]--> times the mass of a planet and radius is $\frac{1}{9}$ <!-- [if gte mso 9]><xml> </xml><![endif]--> times the radius of the planet. The ratio of escape speed from planet to escape speed from moon is ________.