A skier starts from rest at the top of a hill. The skier coasts down and up a second hill whose crest is circular with radius r=36 m. Neglect friction and air resistance. Find the height h (m) of the first hill so that the skier just loses contact with the snow at the crest.

Question

G1 Physics · Accepted Answer

At the crest, just losing contact means N=0, so v²=gr. The first hill is h above the crest, and energy gives mgh=½mv²=½mgr. Thus h=r/2=36/2=18 m.