- #1

flyingpig

- 2,579

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## 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 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

## 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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