Question

1. A skateboarder coasts at a constant velocity toward a ramp with a 15 angle, preparing for the big trick jump. If the frictionless ramp is 3m long, and his initial velocity at the base of the ramp is 5 m/s, calculate his final speed at the end of the ramp?

Answer 1

part of his K.E. becomes gravitational P.E. at the end of the ramp

the height of the end of the ramp is ... 3 m / sin(15º)

final K.E. = initial K.E. - gravitational P.E. =
... (1/2 m 5^2) - [m * 9.8 * 3 m / sin(15º)]

final speed = √[ 2 * final K.E. / m]