Lauren is pedaling down a steep hill on her bicycle and wants to be able to coast up the next hill, which is 25 meters high, without pedaling up the hill at all. What would her speed at the bottom need to be?

Question

50 m/s
71 m/s
7.1 m/s
240 m/s

Answer 1

PE top of next hill=mg*25
KE she must have at bottom=1/2 m v^2

set them equal, solve for v.