fred and barney are pushing a 200 kg crate up a plank, they have to put it on a roller. they apply a force of 1600N to the crate in order to accelerate at .5 m/s^2. the angle of the plank is 20 degrees. find the coefficient of friction.

Answer 1

Forces down the ramp:
m g sin 20
mu m g cos 20

Force up the ramp
1600 N
so
1600 - m g sin 20 - mu m g cos 20 = m (.5)

Answer 2

is the coefficent .16?