Different way to solve projectile motion components?

[wortman]

Different way to solve projectile motion components?

Homework Statement

solve projectile motion formulas for \Theta and v_0
all measurements are in m, t is seconds
y_0=.005
x_0=0
the averages from my trials were:
x=8.775 m
t=1.3 s

Homework Equations

x=x_0+v_0*cos\Theta*t
y=y_0+v_0*sin\Theta*t+.5a_yt^2

The Attempt at a Solution

after plugging in my numbers gives:
for x
6.75=v_0*cos\Theta
which as far as I can see still has two unknowns, where do I go from here?

I'm pretty confused about the y component because I'm not even sure what y is supposed to be. Don't I need a y(max) number first?

 

[Redbelly98]

You don't need ymax necessarily.

What is y when t=1.3s and x=8.775m?

 

[wortman]

Alright, so I got some more insight from my roommate and managed to boil the equations down to:
6.75=v_0Cos\Theta
and
8.28=v_0Sin\Theta

am I headed in the right direction by then solving the x component for v_0=Cos\Theta and then combining it with the y formula to get something like 8.28=6.75Tan\Theta?

BTW I gave the wrong number for y_0. It should be .0125 m. if you are actually checking my work

 

[Redbelly98]

Looks like you're on the right track, though I'm not sure where 8.28=v_0Sin\theta comes from.

 

[wortman]

does 6.37=v_0Sin\theta sound better?

 

[Redbelly98]

Since I don't know what y is, I don't know.

Welcome to PF, by the way.