A science teacher decides to take the top edge of the classroom blackboard
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Work Energy and Power · Work Energy and Power
Problem
A science teacher decides to take the top edge of the classroom blackboard, 2.0m above the floor, as the level of zero gravitational potential energy.
Two identical books, each of mass 2kg, are placed as follows:
Book P is on a wall shelf 1.5m above the floor, while Book Q is on the floor itself.
(i) Calculate the gravitational potential energy of each book with respect to the chosen reference level.
(ii) State whether these potential energy values are positive, negative or zero and give a brief reason for your answer.
(iii) If the reference level is now shifted to the floor, explain how the sign and magnitude of the potential energy of Book P will change.