A laser source is 2.0 in. from the nearest point P on a flat mirror, and the

Question:

A laser source is 2.0 in. from the nearest point P on a flat mirror, and the laser beam is directed at a point Q that is on the mirror and is x in. from P. The beam is then reflected to the receiver, which is x in. from Q. What is x if the total length of the beam is greater than 6.5 in.? See Fig. 17.28.

Fig. 17.28.