A box weighing 100 newtons is pushed up an inclined plane that is 5 meters long. It takes a force of 75 newtons to push it to the top, which has a height of 3 meters.
How do i find the Percent Efficiency in this problem?? PLEASE HELP!!
2007-11-25 12:09:10 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Well, work = force x distance.
If you push a box with force 75 newtons a distance of 5 meters, then the work input is
75 x 5 = 375 Newton-meters.
That you have accomplished is move the box weighing 100 newtons vertically 3 feet. The work output is 100 x 3 = 300 Newton-meters.
So your efficiency is 300/375 = 80%
2007-11-25 12:19:41 · answer #1 · answered by Computer Guy 7 · 5⤊ 1⤋
An easier way then the above is to just find the actual force that should be required to push the box up the angle (will be amount required to prevent the box from sliding down the incline). The extra force is due to friction.
Since someone already give you the answer, the easier way is:
100N box in the above geometry is 100*3/5=60N along the angle. 60N/75N=80%
2007-11-25 12:36:14 · answer #2 · answered by keith w 1 · 0⤊ 0⤋