Max Height of a Projectile

1. Jun 9, 2009

Bobbert

1. The problem statement, all variables and given/known data
Find the max height of a projectile fired at an angle of 30 degrees if it's inital speed is 0.714m/s.
(this is a lab so I have other data that might be needed)
2. Relevant equations

3. The attempt at a solution
0=(0.714sin30o)2+2(-9.81)(d)
d=19.62-0.127449
d=19.49m

Now this answer is not practical at all. There is no way my projectile went that high. Maybe a couple meters, but not 19.5m. Where did I go wrong?

2. Jun 9, 2009

LowlyPion

Maybe it's your math that isn't practical?

Shouldn't you get a result that is a small number divided by a big number?

3. Jun 9, 2009

rock.freak667

If v2=0

then 0=V12-2(9.81)d

$$d=\frac{V_1^2}{2(9.81)}$$

4. Jun 9, 2009

Bobbert

wow, it is way to late. How did I mess that up.