Question

An artillery peice which consistently shoots its shells with the same muzzle speed has a maximum range R. To hit a target which is from the gun and on the same level, the elevation angle of the gun should be.

Answer 1

$R=\frac{u^2}{g}$

$u^2=Rg$

$\frac{R}{2}=\frac{u^{2}sin2\theta }{g}$

$\frac{R}{2}=\frac{Rgsin2\theta }{g}$

$sin2\theta =\frac{1}{2}$

$sin2\theta =sin30$

$\theta =15$