A rescue cable attached to a helicopter weighs 2lb/ft. A 190 pound man grabs the end aof the rope and is pulled from the oceaninto the helicopter. How much workis done in lifting the man if the helicpter is 40 ft above the water.
190 + 2 x 40 for the cable = 270 x 40 = 10,800 but I have a bad feeling I am leaving something out.
The answer I get is 10,800 ft pd but I would like a check for confidence. Thanks
2007-02-24 12:10:35 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Physics
You are correct, 10,800 foot-pounds.
2007-02-24 12:18:03 · answer #1 · answered by Keith P 7 · 0⤊ 0⤋
Work is force x distance
W = (80 + 190) x 40 = 270 x 40 = 10,800 ft-lb
Your calculation is perfectly good - well done.
2007-02-24 14:02:23 · answer #2 · answered by Norrie 7 · 0⤊ 0⤋
The weight of the cable is 80 pounds, but the EFFECTIVE distance is only 20 ft, because half the weight is above 20 ft and half below. Conversely, you can treat it as half the weight of the cable moved the full 40 ft.
2007-02-24 15:32:45 · answer #3 · answered by arbiter007 6 · 0⤊ 0⤋
The Asian dude is correct.
2016-06-16 04:03:10 · answer #4 · answered by Sam 1 · 0⤊ 0⤋