Hi, a projectile is fired with an initial speed of 500 m/s and angle of elevation 30 degrees.

Find the range of the projectile, the max height, and speed at impact

Thanks.

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- Nov 11th 2008, 09:48 AMkhuezyprojectile help
Hi, a projectile is fired with an initial speed of 500 m/s and angle of elevation 30 degrees.

Find the range of the projectile, the max height, and speed at impact

Thanks. - Nov 11th 2008, 11:56 AMArch_Stanton
Firstly, we need to compute the component velocities.

$\displaystyle v_y=v_0 sin \alpha$

$\displaystyle v_x=v_0 cos \alpha$

and duration of this movement:

$\displaystyle v_y=gt \Rightarrow t=\frac{v_y}{g}$

Maximum height is: $\displaystyle h=\frac{gt^2}{2}=\frac{v_y^2}{2g}=\frac{v_0^2sin^2 \alpha}{2g}$

The rage: $\displaystyle x=v_xt=v_0cos\alpha \frac{v_0sin \alpha}{g}=\frac{v_0^2sin \alpha cos\alpha}{g}$

The speed at impact is equal the initial speed. - Nov 12th 2008, 02:34 PMkhuezyhmm
what am I doing wrong w/ the range?

I'm getting a 11km rather than 22km(book) - Nov 12th 2008, 03:06 PMskeeter
because the correct range equation is ...

$\displaystyle \frac{2v_0^2 \cdot \sin{\theta}\cos{\theta}}{g} = \frac{v_0^2 \cdot \sin(2\theta)}{g}$ - Nov 12th 2008, 03:33 PMkhuezythank you
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