physics
posted by steve on .
While a roofer is working on a roof that slants 36 degrees above the horizontal, he accidentally nudges his 85.0 N toolbox, causing it to start sliding downward, starting from rest. If it starts 4.25m from the lower edge of the roof, how fast will the toolbox be moving just as it reaches the edge of the roof if the kinetic friction force on it is 22.0 N?

Well, first find the net accelerating force
Net accelerationforce= weight down the plane  friction
mgSinTheta  22
Set that equal to mass*acceleration and solve for acceleration.
then:
Vfinal^2=Vinitial^2+2*a*d
(Vinitial is zero
solve for Vfinal 
23