What Went Wrong? Calculating the Max Height of a Projectile at a 30 Degree Angle

[Bobbert]

Homework Statement

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)

Homework Equations

V₂²=V₁²+2ad

The Attempt at a Solution

V₂²=V₁²+2ad
0=(0.714sin30^o)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?

 

[LowlyPion]

3. The Attempt at a Solution
V₂²=V₁²+2ad
0=(0.714sin30^o)²+2(-9.81)(d)
d=19.62-0.127449
d=19.49m

Now this answer is not practical at all...

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?

 

[rock.freak667]

If v²=0

then 0=V₁²-2(9.81)d

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

 

[Bobbert]

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