posted by demi .
A motorcycle daredevil is attempting to jump across as many buses as possible (see the drawing). The takeoff ramp makes an angle è = 18.0° above the horizontal, and the landing ramp is identical to the takeoff ramp. The buses are parked side by side, and each bus is 2.74 m wide. The cyclist leaves the ramp with a speed of v = 30.0 m/s. What is the maximum number of buses over which the cyclist can jump?
horizontal speed = u = constant = 30 cos 18 so find u
d = u T
so we need T (total time aloft) to know the horizontal distance, d in the air.
so how long in the air?
initial speed up = Vi = 30 sin 18
so find Vi
v = Vi - 9.8 t
at top v = 0 and t = T/2
T/2 = Vi/9.8
T = Vi /4.9
put that T back in d = u T to find how far it goes in the air