Question

a child is standing in front of a straight plane mirror and his father is standing behind him as shown in the figure the height of the father is double the height of the child what is the minimum length of the mirror required so that the child can completely see his own image and his father's image in the min given that the height of father is 2H

Answer 1

minimum height of the mirror to see boy=h/2

min. height of mirror to see his father's image=2h/2=h

because he want to see his father's full image

so min. height of mirror=h