Answer:
-10.17 J
Step-by-step explanation:
Work done = weight x displacement
weight = 5 pound
= (5 x 4.45) N
= 22.25 N
Displacement = 18 inches
1 inch = 0.0254 m
18 in = 0.4572 m
Work done = 22.25 N x 0.4572 m x cos 180°
= -10.17 J
Thus, the amount of energy used to lift 5 pound object to 18 inches, 10.17 J of energy is used.