A projectile is launched at 36 m/s and travels 100 m horizontally. If it is to be able to just barely clear a 10 m wall, between what two angles should the projectile be launched with respect to the horizontal?

i have almost no idea what to do!

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- Oct 3rd 2009, 04:46 PMtrigunesqangular velocity
A projectile is launched at 36 m/s and travels 100 m horizontally. If it is to be able to just barely clear a 10 m wall, between what two angles should the projectile be launched with respect to the horizontal?

i have almost no idea what to do! - Oct 3rd 2009, 10:15 PMmathaddict
HI

This is my take on it ..

THe projectile has to satisfies two condition

(1) Travel a range of 100 m

(2) able to clear the wall (maximum height) of 10 m

Range , $\displaystyle R =\frac{u^2\sin 2\theta}{g}$

$\displaystyle 100=\frac{36^2\sin 2\theta}{10}$

$\displaystyle \theta=25.25^o$

Now maximum height , $\displaystyle H = \frac{u^2\sin^2 \theta}{2g}$

$\displaystyle 10=\frac{36^2\sin^2 \theta}{20}$

$\displaystyle

\theta= 23.13^o

$

I don understand what it means by between 2 angles .. but the angle should be > 25.25 .