speed at the top of the ramp?

Question

If Evil Kneival drives his motorcycle up a ramp (inclined 30 degrees above the horizotal) and sails over 10 buses (spanning 36 meters) and lands on a similar ramp, what was his speed at the top of the ramp (either one)?

Answer 1

Let his speed be V, with horizontal factor Vh and vertical factor Vv

Vv= sin(30)V = V/2
Vh= cos(30)V= 0.866V

Since he crossed 36 meters in time T

Vh*T = 36
T = 36/Vh = 41.6/V

Now he had a vertical speed of 0.5V with an acceleration of -9.8 m/s^2, and since he landed at the same elevation he started with, his net vertical motion is 0.

d= 1/2aT^2 + vT
0= 1/2*(-9.8)T^2 + 0.5VT

replace T by 41.6/V

0 = 1/2(-9.8)(41.6/V)^2 + 0.5V(41.6/V)
0 = -8480/V^2 + 20.8
20.8 = 8480/V^2
V= sqrt(8480/20.8) = 20.2 m/s (about 72km/h)