Ok i got the first part of this question but i can't figure out the second part...help!
In raising a 4600 N piano with a pulley system, the workers note that for every 2 m of rope pulled down, the piano rises 0.2 m. Ideally, how much force is required to lift the piano?
460 N(got that)
now...
(b) If the workers actually pull with 2500 N of force to lift the piano, what is the efficiency of the pulley system?
2007-02-18 14:08:32 · 2 answers · asked by Jane A 3 in Science & Mathematics ➔ Physics
Efficiency = (Work out) / (Work in)
Work = F*d
So
Efficiency = (4600N*0.2m)/(2500N*2m) =18.4%
2007-02-18 14:15:00 · answer #1 · answered by Dennis H 4 · 0⤊ 0⤋
efficiancy is the ratio of paintings (or capability) out while in comparison with paintings put in. ability is measured in watts = J/s. ability score ( enter) = 1200W output = 80% of 1200 so capability wasted is 20% 20% = 0.2 0.2 x 1200 = 240J/s used for 30 minutes = 30 x 60 seconds complete capability wasted = 30 x 60 x 240 j
2016-11-23 17:42:40 · answer #2 · answered by ? 4 · 0⤊ 0⤋