Let h = (v o^2 / 4.9) sin theta cos theta model the horizontal distance in meters traveled by a projectile. If the initial velocity is 52 meters/second, which equation would you use to find the angle needed to travel 200 meters?

A. 551.84sin(2theta)=200
B. 275.92sin(2theta)=200
C. 10.61 sin(2theta)=100
D. 200 sin(2theta)=200

Question

Let h = (v o^2 / 4.9) sin theta cos theta model the horizontal distance in meters traveled by a projectile. If the initial velocity is 52 meters/second, which equation would you use to find the angle needed to travel 200 meters? 

A. 551.84sin(2theta)=200 
B. 275.92sin(2theta)=200 
C. 10.61 sin(2theta)=100 
D. 200 sin(2theta)=200

anonymous · Answer

I do not know where to go from this stage:

$$551.84\sin \Theta$$

kropot72 · Answer

You should use the double angle formula:
$$\large \sin 2\theta=2 \sin\theta \cos\theta$$

anonymous · Answer

just tell me the proper equation

kropot72 · Answer

Then we get
$$\large 200=\frac{52^{2}}{4.9}\times \frac{\sin 2\theta}{2}$$

anonymous · Answer

Oh I understand! So that would get me the answer to be B right?

kropot72 · Answer

Correct.

anonymous · Answer

Great! Thank you! It's always setting up the equation that gets me.

kropot72 · Answer

np. You're welcome :)