A block of mass m is initially held in place on the left side of a track at a distance h above the bottom of the track. The track is completely frictionless, with the exception of a rough horizontal section of track of length h which has a coefficient of kinetic friction μ = 0.15. If the block is released from rest, how many times does the block completely cross the rough section of track before it stops?
The Attempt at a Solution
So I have worked out the height to be 0.85 m, but am stuck on finding an expression for when the ball will stop I have what I think it is
x=number of times without stopping= v^2/2gh
does this see right, and I worked out v = 11.43 but when I plug it in I get 7.84 times... in the answer booklet it says seven but im not sure if thats because you cant round up because it doesnt make sense so they round down to 7??