How many seconds will it take 10.0 hp motor to lift a 2,000 lb elevator a distance of 20 ft? (b) What was the average velocity of the elevator?
2007-09-26 11:35:05 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
well.. 1 horsepower is 550 pound feet per second so 10 would be 5500 pound feet per second and 2000 pounds raised 20 feet is 40000 pound feet of work.. divide 40000 by 5500 to get the number of seconds.
You could convert to SI units, but... the math is easier if you don't. I get the same result either way.
2007-09-26 11:45:18 · answer #1 · answered by ? 3 · 1⤊ 0⤋
1. Change everything to Si units.
2. Remember that 1 HP (electric) = 746 W = 746 J/s
3. Remember that work is change in potential or kinetic energy.
4. Ep = mgh where m is mass, g is 9.8 m/s² and h is meters.
Plug 'n chug. The hard part is going to be the units conversion(s)
Doug
2007-09-26 11:44:04 · answer #2 · answered by doug_donaghue 7 · 0⤊ 0⤋
when it gets there, it gets there. if you want it there faster, get more horse power.
2007-09-26 11:43:13 · answer #3 · answered by Anonymous · 0⤊ 0⤋