Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Efficient prblm please help

  1. Jan 8, 2004 #1
    a motor furnishes 120 hp (746W=1hp) to a hoisting device that lifts 5000kg load to height of 13.0 meters in a time of 20.0 seconds. Find the efficiency....please help sum1 at least a formula?????
  2. jcsd
  3. Jan 8, 2004 #2
    Energy = power * time. Figure out the ratio of the energy converted in lifting the 5000kg mass to the total energy that was used by the machine.
    Last edited: Jan 8, 2004
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook