A certain satellite has a kinetic energy of 7.5 billion joules at perigee (closest to Earth) and 6.5 billion joules at apogee (farthest from Earth). As the satellite travels from apogee to perigee, how much work does the gravitational force do on it?

Question

Physics

Krista Walls

12 July, 05:16

A certain satellite has a kinetic energy of 7.5 billion joules at perigee (closest to Earth) and 6.5 billion joules at apogee (farthest from Earth). As the satellite travels from apogee to perigee, how much work does the gravitational force do on it?

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Answers (1)

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Braveheart · Answer 1

Work Done by the earth's gravitational force on the satellite as it travels from apogee to perigee is

W = F*D*Cos90° = 0

Explanation:

Although there is a change in the kinetic energy of the satellite at the apogee and perigee, the work done by the earth's gravitational force on the satellite is Zero.

W = F. D, F is the gravitational force, D is the displacement. Both F and D are vectors and perpendicular to each other. That is, the angle between F and D is 90°.