Question

A rifle with a muzzle velocity $1500{fts}^{-1}$ shoots a bullet at a small target $150ft$ away. How high above the target must the gun be aimed so that the bullet hits the target?

• A. $2.02$ inch
• B. $1.72$ inch
• C. $1.82$ inch
• D. $1.92$ inch

Answer 1

The correct option is D $1.92$ inch

Time taken to reach target by bullet $=t=\frac{150}{1500}=0.1s$
Due to $g,$ displacement of bullet along vertical direction $y=0+\frac{1}{2}\left(9.8\right){\left(0.1\right)}^2=4.9m=0.049cm=1.92inch$
So gun must be above the target by $1.92inch$