Answer:
v = √(2 MGh) / R
Explanation:
Assuming that h is much smaller than R, we can say the acceleration of gravity is approximately constant during the fall.
Potential energy = Kinetic energy
mgh = 1/2 mv²
v = √(2gh)
v = √(2 (MG/R²) h)
v = √(2 MGh) / R