- #1
flyingpig
- 2,579
- 1
Homework Statement
I made this one up and now i can't solve it (tada...)
[PLAIN]http://img577.imageshack.us/img577/5081/probloem1.jpg
OKay so the biker runs off the ramp and leaves the ramp at the tip with some initial velocity v0
I will give some numerical values to make this easier
ϕ = 30 degrees
g = -10m/s2
v0 = 20m/s
y = 10m
h = 20m
d = 5m
x = 30m
OKay three goal
1) Set up the motion equations for the biker
2) Find the max height reached
3) Find when it lands on top of the new building
The Attempt at a Solution
1) I have most problems with this one, especialyl when I cannot decide if ϕ is the correct angle. That is if the biker flies off from an angle different from ϕ
[tex]y(t) = -5t^2 + |20|sin30t + (10 + 20)[/tex]
[tex]x(t) = |20|cos30t[/tex]
2)
[tex]y(t) = -5t^2 + |20|sin30t + (10 + 20) = -5t^2 + 10t + 30 = -5(t^2 - 2t - 6) = -5(t^2 -2t + 1 - 1 - 6) = -5((t -1)^2 - 7) = -5(t-1)^2 + 35[/tex]
So ymax = 35m
3) So basically h - d = 20 - 5 = 15
[tex]15 = -5^2 + 10t + 30[/tex]
[tex] 0 = -5t^2 + 10t + 20[/tex]
[tex]t = 1 + \sqrt{5}[/tex]
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