Question

The sun exerts a force of 4.0 x 1028 N on the earth and the earth travels 9.4 x 1011 m in its annual orbit around the sun. How much work is done by the sun on the earth in the course of a year?

Answer 1

Answer:

The sun exerts a force of 4.0 x 1028 N on the earth and the earth travels 9.4 x 1011 m in its annual orbit around the sun. How much work is done by the sun on the earth in the course of a year?

Explanation:

Answer 2

Answer:

ZERO.

This is because the Force of attraction between sun and the earth is along the radius and the displacement at any moment is at right angles to the force of attraction. Hence work done = Force*Displacement*Cos x. Where x is the angle between line of action of force and the displacement direction. As the x is 90 degrees. Therefore Cos x is zero implies the work done is zero.