The concept of gravitational potential energy depends on the choice of zero level
PHYSICS · Multi-part · CBSE · Physics · Work and Energy · Work and Energy
Problem
The concept of gravitational potential energy depends on the choice of zero level. Answer the following questions to illustrate this idea:
(a) Define gravitational potential energy of a body kept at a height above a chosen reference level.
(b) A stone of mass 2kg is placed on a table 0.8m high. Student X takes the laboratory floor as the reference level, whereas Student Y takes the table-top itself as the reference level. Explain, without any numerical calculation, how the values of potential energy reported by the two students will differ and why the physical situation remains unchanged despite this difference.
(c) If the stone is moved from the table-top to a shelf 2.0m above the table, show that the work done in this transfer will be the same for both students irrespective of their chosen reference levels.