A box slides down a plank of length d that makes anangle of θ with the horizontal as shown. μk is thekinetic coefficient of friction and μs is the staticcoefficient of friction.
a) Enter an expression for the minimum angle θ (in degrees) thebox will begin to slide.
b) Enter an expression for the nonconservative work done bykinetic friction as the block slides down the plank. Assume the boxstarts from rest and θ is large enough that it will move down theplank. Â
c)
| For a plank of anylength, at what angle θ (in degrees) will the final speedof the box at the bottom of the plank be 0.75 times the final speedof the box when there is no friction present? Assume μk= 0.39. |
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