Answer:
No work is done if the direction of motion is perpendicular to the force.
Explanation:
The speed of a satellite in a circular orbit changes in direction but not in magnitude, that is why it remains constant, but its velocity is changing along the time. Now, in this case, the direction of the motion is perpendicular to the acting force, which is the centripetal force, and knowing that the work is proportional to the scalar product of force and displacement, no work is done on the satellite.
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