A crate of mass 11.5 kg is pulled up a rough incline with an initial speed of 1.5 m/s. The pulling force is 100 N parallet to the incline, which makes an angle of 21 degrees with the horizontal. The coefficient of kinetic friction is .4, and the crate is pulled 4.05 m.
I've tried to find the amt of mechanical energy lost due to friction using {change in kinetic + change in potential = change in thermal), but my answer is not coming out correctly. Any suggestions?
2006-11-04 00:37:28 · 2 answers · asked by krisski 3 in Science & Mathematics ➔ Physics
you can use
work = delta ke + delta PU
(100*4.05) - ( 11.5*cos21*.4*4.05)= mechanical enrgy lost
so
mechanical enrgy lost = 387.607 j
2006-11-04 00:47:33 · answer #1 · answered by mms 3 · 0⤊ 1⤋
I think you need only to consider the coefficient of friction, the force normal to the surface, and the distance moved to determine the wasted energy.
2006-11-04 00:59:06 · answer #2 · answered by Richard S 6 · 1⤊ 0⤋