A 70kg student, happy to see snow in early
November, rushes out to sled on a hill with a 10kg
sled. They start h=12m above a horizontal plane.
How fast are they moving by the time they reach
the bottom of the hill? (assume the coefficient of
friction is zero here) After a short distance the
reach a point where there are some dry leaves are
scattered producing an effective coefficient of
friction uk=0.4. How far do they travel through the leaves before they
come to rest?
Use the fundamental principle