Planets

Two planets have the same mass, M. Each planet has a constant density, but the density of planet 2 is twice as high as that of planet 1. Identical objects of mass m are placed on the surfaces of the planets. What is the relationship of the gravitational potential energy, U_(1) on planet 1 to U_(2) on planet 2?

Planet A has a mass and radius twice that of Planet B. The escape velocity from Planet A is

Red Planet is

Two planets of mass M and 16M of radius a and 2a respectively, are at distance 10a . Find minimum speed of a particle of mass m at surface of smaller planet so that it can reached from smaller planet to larger planet.

Planet A has double the radius than that of Planet B. If the mass of Planet A is 4 times heavier than the mass of Planet B, which of the following statements regarding weight of an object is correct?