Answer:
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