Under what conditions will the bullet hit the tin can?

Question

A rifleman raises his gun and aims it at a tin can target on a shelf in the shooting range. If the bore of the gun is pointed straight at the can, under what conditions will the bullet hit the tin can?

Answer 1

The bullet needs to get there in time t such that
y = (1/2)*g*t^2 is less than 1/2 the dimension of the can.