A24 kg rock is resting on the floor. how much potential energy dose it have?

Potential energy =

                   (mass) x (gravity) x (height above the reference level) .

-- Relative to the floor, the rock's potential energy is

                     (24 kg) x (9.8 m/s²) x (0)  =  zero .

-- Relative to the basement floor, 3 meters below, its potential energy is

                     (24 kg) x (9.8 m/s²) x (3 m) = 706 joules (rounded) .

-- Relative to the roof, 6 meters above, its potential energy is

               (24 kg) x (9.8 m/s²) x (-6 m) = negative 1,411 joules (rounded)