A rifle that shoots bullets at 460 m/s is to be aimed at a target 47.0 m away. If the center of the target is level with the rifle, how high above the target must the rifle barrel be pointed so that the bullet hits dead center? (Neglect air resistance.)

Answer 1

xo=x original vo=v original
So first in the horizontal direction
x=xo+vot+.5at^2
x=vot
t=47/460=0.102seconds to hit target
then for vertical direction
x=xo+vot+.5at^2
x=.5at^2
x=.5(9.8)(0.102)^2=0.0512 m above target