The beam must strike the mirror half way up from his feet to his eyes. The angle is incidence is therefore
tan^-1 [(1/2)*1.9/4.4] = tan^-1 .21591
= 12.2 degrees
A person stands 4.4 m in front of a wall that is covered floor-to-ceiling with a plane mirror. His eyes are 1.9 m above the floor. He holds a flashlight between his feet and manages to point it at the mirror. At what angle of incidence must the light strike the mirror so the light will reach his eyes?
1 answer