Question

A 100 kg object is taken to a height of 370 km above the Earth's surface.

A)What is the object's weight at this height?

Answer 1

As we know that the mass is universally constant and remains constant.

So, we have a constant mass m = 100 kg

Weight depends on gravitational field strength g' (N/kg) at distance R' = Re + 370 km from center of the Earth. (W = mg')

As g is inversely proportional to R² (g = k/R²)

g' / ge = (Re)² / (R')² (ge = 9.80N/kg, Re (radius of earth) = 6371km, R' = 6371+370 = 6741 km)

g' = 9.80 x (6371 / 6741)² = 8.75 N/kg

Hence, weight of the object at a height of 370 km = mg' = 100 kg x 8.75 N/kg

=> W = 875 N