A 200-pound boy lifts a 40-kilogram box off of the floor 1.3 meters in 0.7 seconds. His brother lifts a 48-kilogram box off the floor 0.9 meters in 0.6 seconds. Which boy is more powerful? Explain.

Answer 1

Wb = m*g = 40kg * 9.8N/kg = 392 N, = Wt.
of the box.
P1 = F*d/t = 392 * 1.3/0.7 = 728 J/s =
728 Watts.

Wb = 48kg * 9.8N/kg = 470.4 N.
P2=470.4 * 0.9/0.6=706. J/s=706Watts.

The 1st boy is more powerful.