Answer:
(a) 13536.10J
(b) 27072.20J
Step-by-step explanation:
(a) Height of tank (h) = 4 feet = 4/3.2808 = 1.22m
Volume of water in full tank = 4ft×5ft×4ft = 80ft^3
Volume of water in half tank = 1/2 × 80ft^3 = 40ft^3
Density of water = 62.4lb/ft^3
Mass of water = density × volume = 62.4 × 40 = 2496lb = 2496×0.45359kg = 1132.16kg
Work done to empty half of the tank = mgh = 1132.16×9.8×1.22 = 13536.10J
(b) Work done to empty all of the tank = 2 × work done to empty half of the tank= 2 × 13536.10J = 27072.20J
