A bullet is fired horizontally aiming at an object which starts falling at the instant the bullet is fired. Show that the bullet will hit the object.

Explanation

The situationis shown in ure. The object stasrts falling from the point B. Draw a vertical line BC through B. Suppose the bullet reaches the line BC at a point D and it takes a time t in doing so.

Consider the vertical motion of the bullet. The initial vertical velocity =0. The distance travelled vertically `=BD=1/2 gt^2`. In time t the object also travels a distance `1/2gt^2=BD.` Hence at time t, the object will also be at teh same point D. Thus, the bullet hits the object at point D.