The floor of the basement of a house is 3.0 m below ground level, and the floor of the attic is 4.5 m above ground level.
(a) If an object in the attic were brought to the basement, the change in potential energy will be greatest relative to which floor: (1) attic, (2) ground, (3) basement, or (4) all the same? Why?
(b) What are the respective potential energies of 1.5-kg objects in the basement and attic, relative to ground level?
(c) What is the change in potential energy if the object in the attic is brought to the basement?