A snowboarder glides down a 60-m-long, 15∘ hill. She then glides horizontally for 10 m before reaching a 20 ∘ upward slope. Assume the snow is frictionless.
A.) What is her velocity at the bottom of the hill?
B.) How far can she travel up the 20 ∘ slope?
How would I solve this?
peterpan
Favorite Answer
A)
1/2 m v^2 = m g d sin@
v = (2 g d sin@)^1/2
v = (2*9.8*60*sin15)^1/2 = 17.45 m/s
B)
due to energy conservation
she returns to the same height of the starting point
h2 = h1 = d1 / sin@1 = 60*sin15 = 15.53 m
then she travels a distance d2
d2 = h2/ sin@2 = 15.53 / sin20 = 45.4 m
or
m g d2 sin@2 = m g d1 sin @1
d2 = d1 sin@1 / sin@2 = 60*sin15 / sin20 = 45.4 m