physics
posted by jen .
a 2.0kg block is pushed against a spring that has a force constant of 10 n/m. the spring is compressed 10 cm. when the block is released, it slides across a rough surface for 25 cm before it stops. find the coefficient of friction between the block and the surface.

work done on spring = potential energy of block.
(1/2) k x^2 = .5* 10 * .01 = .05 Joules
friction force * distance = .05 Joules
mu m g (.25) = .05
so
mu = .05/(.25*2*9.8)