Calculate the work done by the force of gravity when a satellite moves in an orbit of radius 40 000 ...........

General Science (DRDO) (Phase-I and II) Physics

Calculate the work done by the force of gravity when a satellite moves in an orbit of radius 40,000 km around the earth.

0 J

8,000 J

4,000 J

4,00,000 J

Explanation:

- The concept of work done by gravity: Gravity is a conservative force. When it acts, work is calculated by the formula: Work = Force × Displacement × cos(?).

- Orbital motion: A satellite in a circular orbit is always at a constant distance from Earth, which means there's no displacement due to the force of gravity. Gravity acts perpendicular to the direction of motion.

- Work done is zero: Since the force of gravity is perpendicular to the displacement in a stable orbit, the work done by gravity is zero.

- Relevant calculations: The angle ? is 90 degrees for circular orbital motion, making cos(?) = 0, hence Work = 0.

- Option 1: 0 J is the correct answer.