posted by Anonymous .
20.) A piano has been pushed to the top of the ramp at the back of a moving van. The workers think it is safe, but as they walk away, it begins to roll down the ramp.
If the back of the truck is 1.5 above the ground and the ramp is inclined at 29, how much time do the workers have to get to the piano before it reaches the bottom of the ramp?
In the real world, a piano has considerable weight and therefore friction, which would reduce the net force, and acceleration down the plane.
weight down the plane mg*cos29.
weight down the plane=m*a
vf= sqrt (2ad)=sqrt (2*a*1.5/sin29)