posted by Julius on .
A student is skateboarding down a ramp that is 5.5 m long and inclined at 19° with respect to the horizontal. The initial speed of the skateboarder at the top of the ramp is 2.9 m/s. Neglect friction and find the speed at the bottom of the ramp.
Apply conservation of energy. Neglect the rotational kinetic energy of the wheels, which will make a small difference since the wheels weigh much less than the skateboarder.
(M/2)[V2^2 - V1^2] = M g deltaH
= M g *5.5 sin 19
V1 = 2.9 m/s
Cancel the M's and solve for V2, the final velocity.
V2^2 - (2.9)^2 = 2*9.81*1.791 = 35.13
V2^2 = 35.13 + 8.41
V2 = 6.60 m/s