(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I made this one up and now i can't solve it (tada...)

[PLAIN]http://img577.imageshack.us/img577/5081/probloem1.jpg [Broken]

OKay so the biker runs off the ramp and leaves the ramp at the tip with some initial velocity v_{0}

I will give some numerical values to make this easier

ϕ = 30 degrees

g = -10m/s^{2}

v_{0}= 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

3. 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 y_{max}= 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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# Kinda embarrassing to ask about setting up this simple kinematics eqtns

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