Originally Posted by
atb5161
3 sets of 5 reps at, say 315lbs. Assume it takes 15 seconds to complete 5 reps. Assume you take 3 minutes rest between sets. Assume the bar travels, like, 2ft from the bottom of the squat to the top.
total work done = (315lbs*2ft)*5 = 3150 lbf
total time to complete work = (15s*5)+(180s*4) = 795s
average power for sets across = 3150/795 = 3.96 lbf/s
For comparison let's figure out the average power output of me doing "grace" (30 reps of 135lb clean +jerk). My grace time is pretty bad, like, 4 minutes. I stand at 5'7", so lets call my overhead position an even 7' above the ground.
total work done = 135lb*7ft*30 = 28350 lbf
total time to complete work = 4*60s = 240s
average power during grace = 28350/240 = 118.125 lbf/s
For reference, a common unit of horsepower is equal to 550 ftlbs/s
Is any of this useful? I dunno, it probably depends on context. If i have to lift a car off my friend, I'd rather be the non-powerful guy that can squat 315 for reps. Likewise if I have to carry a 100lb sack of supplies 200 yards across a dangerous battlefield, I'd rather be the guy who doesn't have to stop and take a breather half way through. Either way, I like physics.
I hope I didn't make an error