Question

The work done by a force:
A) is independent of the frame of reference
B) is the same in all reference frames
C) is the same in all inertial frames
D) None of these

Answer 1

Hint : Work is done whenever a force moves something over a distance. We can calculate the energy transferred, or work done, by multiplying the force by the distance moved in the direction of the force.

Complete step by step answer:
The work done by a force is dependent on the frame of reference. The reasoning for this assertion is as follows:
The force that acts on an object is invariant which means that the force that acts on a body is the same in all references of frames. So, for example, if an object is falling under gravitational acceleration, there will always be a gravitational force acting on the object such that it is constant whether we are moving in a frame of reference along with the falling object or whether we are stationary with respect to the ground.
However, the displacement of the object as it is falling towards the ground, the displacement of the object depends on the frame of reference. If we were moving with the falling object, the displacement of the object will be zero while if we are stationary with respect to the object, the displacement will be non-zero.
Since the work done by a body is the product of work done and the displacement of the object, the work done will largely depend on the displacement of the object which depends on the frame of reference.
So, option (D) is correct since all the other options contradict the properties of force and work done.

Note:
Irrespective of the frame of reference, the law of conservation of energy will hold true. So even if work is not being done in a frame of reference, it will be compensated by the displacement of some other object and energy will be conserved.