Question

a mass is released from rest from a height of 4m. it slides down a frictionless ramp then along a 20 degree incline section of rough track. how far does it slide along the incline before coming to rest?

friction coeficient= .2
? help!

thanks!

Answer 1

The first thing is to figure the height it fell.

Let the ramp be length L along the sliding service, and d the distance it slid.

Final height h= (L-d)/cos20

height it fell then total is
Heightfell=4-(L-d)/cos20
energy used in stopping is
weight normal*mu*distance
mgcos20*.2*d
so, using energy...

1/2 m(4-(L-d)/cos20)=mgcos20*.2*d
so solve for d. You didn't mention L, the length of the ramp, but you have to have it.