How do you Calculate the power output of a Person that bench presses 150 pounds 30 times in 10 seconds and moves the barbell a distance of 24 inches during each press?

Power is defined as work over time. Thus, we must first calculate the work involved in moving the barbell. W = Fd = 150 lbs * 2 ft = 300 ft-lbs per rep The work expended over the entire work out is thus 30 * 300 ft-lbs = 9000 ft-lbs. Since P = W/t, the power output is P = 9000 ft-lbs/10s = 900 ft-lbs/sec, which is about 1222 watts.