The moon is the earth's nearest neighbor in space the radius of the moon is approximately one quarter of the earth's radius and it's mass is one eightieth of the earth's mass.(a)calculate the weight of an object with a mass of 50.0kg on the surface of the moon.(b)calculate the weight of an object with a mass of 80.0kg when it is at a distance equal to three times the moon's radius away from the moon

2 answers

(a) Since the acceleration of gravity at the surface is proptional to M/R^2, it's value on the moon is (1/80)*4^2 = 16/80 or 1/5 of the value on Earth.
The actual value is closer to 1/6.
Weight = (1/5) M*g, where M = 50 kg
and g -= 9.8 m/s^2

(b) Three moon radii from the surface, the acceleration of gravity is 1/9 of the value at the moon's surface.
Weight = (1/45) M*g, where M = 80 kg
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