A light spiral spring with an elastic constant of 
is attached to the top of a slope inclined at an angle 
. A log of mass 200 g is attached to the spring and is held so that the spring is not deformed (see the figure below).
When the log is released, it starts to slide down the slope. By how much is the spring stretched when the log stops if the coefficient of friction between the log and the slope is 0.2?
How much work does the log receive from gravity?
A log on a slope
