A satellite orbits the Earth at a constant altitude in a circular orbit. The satellite’s mass is 1000 kg, and it is moving at a speed of 7.8 km/s. If the altitude of the satellite is 300 km above the Earth’s surface, what is the gravitational force acting on the satellite?
a) 1000 N
b) 5000 N
c) 8000 N
d) 10000 N