Question

During the motion of a planet from perihelion to epihelion the work done by gravitational force of sun on it is
(1)zero
(2) negative
(3) positive
(4)may be positive or negative
Pls give reason also

Answer 1

Answer:

I think zero is right answer gravitional force

Answer 2

Explanation:

Because the displacement of the planet from perihelion to aphelion is opposite to the direction of its gravitational pull, so it is negative.

The force exerting on the planet due to the gravity is alway toward to sun. When the planet swings from the closest point, perihelion, to the furthest point, aphelion, the effective displacement is away from the sun, not toward it. When the force and its displacement are in opposite direction, the work done by the force is said to be negative.