COMEDK2024PhysicsGravitation
A particle of mass 1 kg is kept on the surface of a uniform sphere of mass 20 kg and radius 1.0 m . The work to be done against the gravitational force between them to take the particle away from the sphere is
Options
- A0.5 10⁻⁹ ~J
- B1.334 10⁻⁹ ~J
- C2532 10⁻⁹ ~J
- Dzero
Correct answer
B. 1.334 10⁻⁹ ~J
Step-by-step solution
Potential at the surface of earth, V=- G M R aligned & =- 6.67 10⁻¹¹ 20 1 & =-1.334 10⁻⁹ ~J / K aligned i.e., 1.334 10⁻⁹ ~J work is done to bring a mass of 1 kg from infinity to the surface of sphere. Hence, the same amount of work will have to be done to take the particle away from the surface of sphere. W=1.334 10⁻⁹ ~J