- #1
Sungura
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Homework Statement
A motorcyclist wants to jump 20 cars placed side-by-side, making the jump 30m long (coming back to the initial height). Assume that the ramp is placed at an angle of 30 degrees from the horizontal.
a. Calculate the initial velocity required to make the jump.
b. Assuming the motorcycle bounces elastically on the ground (rebounding at the same angle and speed), calculate the change in momentum of the motorcycle (mass = 500kg)
c. If the motorcycle is in contact with the ground for 0.25s, find the average force exerted by the ground on it.
Homework Equations
x=x0+v0t+(1/2)at^2
y=y0+v0t−1/2gt^2
The Attempt at a Solution
I'm not entirely sure if there are more equations I should be using, but I began with trying to use the x equation to solve for time. I assumed a was zero, since there is no acceleration in the x direction, and that x0 was zero, since we start at the origin. So, ending up with x=v0cosθ*t (Right here I'm not sure where the cos comes from, I kind of just stuck it there because I remember seeing such an equation before) I solved for t, ending up with t=30/v0cos(30).
I plugged this t back into the x equation, but I kind of get lost in the math at that point, since I seem to have to pull the v0 out of the right side of the equation somehow.
part (a.) seems to be my biggest problem, so if I get a little assistance with that I think it'll make (b.) and (c.) much easier to solve, since it's just impulse and momentum.