An object of mass m is dropped from height h above a planet of mass m and radius r .

find an expression for the object's speed as it hits the ground.
express your answer in terms of the variables m, m,h, r and appropriate constants.

Explanation:

The initial mechanical energy of the object, when it is located at height h above the the planet, is just gravitational potential energy:

where

G is the gravitational constant

M is the mass of the planet

m is the mass of the object

R is the radius of the planet

h is the altitude of the object

When the object hits the ground, its mechanical energy will sum of potential energy and kinetic energy:

where

v is the speed of the object at the ground

Since the mechanical energy is conserved, we can write

and solving for v, we find

the answer is neither ball has a charge.

because if they were both positively charged, they will repel each other.

if they were positively and negatively charged, they will seek.

3.2x10^7