Simple projectile motion problem

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jayman011
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Hi, I am a new member on your site, but been a long time lurker for the many times the forums have saved me lots of grief. Heres the problem, its a simple angle of elevation problem on our online Calculus homework site called webwork, I am fairly certain I know how to work this problem, but the server will not accept the answer, maybe someone can spot where I am messing up.

Homework Statement



A gun has a muzzle speed of 80 meters per second. What angle of elevation should be used to hit an object 190 meters away? Neglect air resistance and use as the acceleration of gravity.

Homework Equations



R = (V^2) (sin(2A)) / g

The Attempt at a Solution



Ive solved the equation for alpha numerous times

190=80^2(sin(2A)/9.8

A=(sin^-1((190*9.8)/80^2))/2

Get 0.1476 radians in the calculator, but it don't like it, checked to make sure i was in radians, even solved in degrees and converted to radians, still not right, any help would be greatly appreciated.
 
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Looks good to me...
0.1476 rad [itex]\approx[/tex] 8.457[itex]^\circ[/tex][/itex][/itex]