Rocket Lab @ Angles: Predicting Distance of Launch

[Hellsing834]

Homework Statement

I need to predict how far a rocket will land given:

Delta Y = 2.032 (80 in ) - Height it will be shot from.
Angle - 35 (degrees)
My Average velocity is 23.3 m/s.

I need to repeat this for angles 40-60 [Increments of 5]

Homework Equations

I have these equations that i am using.

Vy = V(average) x sin (theta)
Vx = V(average) x cos (theta)
X = V(average) x cos (theta) * Time
T = (2*V(average))/ g

The Attempt at a Solution

For the first scenario i did the calculations and i am getting 55.3 m, but i know that is not right because we shot the rockets today, and mine did not even go past 40m. I did 3 trials, and each time it was between 20-40 m.

 

[LowlyPion]

Homework Statement

I need to predict how far a rocket will land given:

Delta Y = 2.032 (80 in ) - Height it will be shot from.
Angle - 35 (degrees)
My Average velocity is 23.3 m/s.

I need to repeat this for angles 40-60 [Increments of 5]

Homework Equations

I have these equations that i am using.

Vy = V(average) x sin (theta)
Vx = V(average) x cos (theta)
X = V(average) x cos (theta) * Time
T = (2*V(average))/ g

The Attempt at a Solution

For the first scenario i did the calculations and i am getting 55.3 m, but i know that is not right because we shot the rockets today, and mine did not even go past 40m. I did 3 trials, and each time it was between 20-40 m.

Maybe the 23m/s is not accurate?

 

[Hellsing834]

I believe that it is accurate because i compared these results with the same lab we did last year, and the answer is close.

 

[LowlyPion]

I believe that it is accurate because i compared these results with the same lab we did last year, and the answer is close.

Perhaps you would do better to use a range equation that was more of the form:

$$Range = \frac{V_o^2*Sin2\theta}{g}$$

This of course does not take into account the height you launch it from.

 

[Hellsing834]

See, even with that equation, my answers comes in the 50's like my original.

 

[LowlyPion]

See, even with that equation, my answers comes in the 50's like my original.

Unfortunately it doesn't take into account how long the rocket burns. Since it is a rocket it will accelerate over a distance that may be greater than 2m.