Question

The gravitational force F exerted by the earth on an object having a mass of 100 kg is given by the equation

F =


4,000,000



d2

where d is the distance (in km) of the object from the center of the earth, and the force F is measured in newtons (N). For what distances will the gravitational force exerted by the earth on this object be between 0.0004 N and 0.01 N?

Answer 1

F = 4,000,000 / d²

For F = 0.0004 N,
d = √(4000000 / 0.0004)
d = 100,000 km

For F = 0.01 N,
d = √(4000000 / 0.01)
d = 20,000 km

The distance must be between 20,000 km and 100,000 km