Question

4. A 1,000-kilogram satellite completes a uniform circular orbit of radius 8.0 x 10 meters as

Answer 1

Answer:

Zero

Explanation:

The work done by a force on an object is given by:

$W=Fd cos \theta$

where

F is the magnitude of the force

d is the displacement of the object

$\theta$ is the angle between the direction of the force and the displacement of the object

In this situation, the force is the force of gravity acting on the satellite. This force always points towards the centre of the trajectory, so it is always perpendicular to the direction of motion of the satellite (since the orbit is circular), so $\theta=90^{\circ}$ and $cos \theta =0$. Therefore, the work done by gravity is also zero.