# Answer to Question #26162 in Mechanics | Relativity for fatma

Question #26162

Does the sun do any work on earth, when earth revolves around the sun in a perfectly circular orbit? Justify the answer.

Expert's answer

for a constant force that is not directed along the line, followed by the particle work equals:

A = F*d*cos(θ)

where

θ is the angle between the force vector and the direction of movement;

F - magnitude of force

d - distance

In our case force and direction of motion is perpendicular, so θ=90

Therefore:

cos(90)=0 => A=0 in each moments of time.

Answer: the sun doesn't do any work on earth, when earth revolves around the sun in a perfectly circular orbit.

A = F*d*cos(θ)

where

θ is the angle between the force vector and the direction of movement;

F - magnitude of force

d - distance

In our case force and direction of motion is perpendicular, so θ=90

Therefore:

cos(90)=0 => A=0 in each moments of time.

Answer: the sun doesn't do any work on earth, when earth revolves around the sun in a perfectly circular orbit.

## Comments

## Leave a comment