Problem : A laserbeam strikes a vertical surface at an angle of 48 ^o . The reflected beam can be seen as a spot on a horizontal surface. The spot is 10 meters away from the point of incidence on the vertical surface. How far is the horizontal distance from the spot to the vertical surface?

Problem : In a dark room a beam enters through a pinhole 5 meters above the floor, reflects off a mirror 2 meters from the wall where it entered, and then forms a spot on the opposite wall 2.5 meters from the floor. How wide is the room?

Solution for Problem 2 >>

The angle between the beam and the floor is given by tan^-1(5/2) = 68.2 ^o . Thus the angle of incidence is the complement of this, 21.8 ^o . This is equal to the angle of reflection, so the angle between the floor and the reflected beam is also 68.2 ^o . To find the distance from the point of incidence to the far wall we have tan(68.2 ^o ) = 2.5/dâá’d = = 1 . Therefore the room is 1 + 2 = 3 meters wide.

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Problem : A mirror on a wall reflects sunlight onto the floor. The mirror is oriented vertically, directly facing the sun and has dimensions 0.7 meters × 0.7 meters, with its base 1 meter from the floor. If the sun if 50 meters above the horizon, how large is the patch of sunlight on the floor?

Problem : Two mirrors are oriented at right angles to one another, forming a so-called corner reflector. Prove that the path of the light entering this system is antiparallel to the path of the light leaving the system.

Problem : What happens if we modify the situation in the previous problem (two plane mirrors oriented at right angles) to some angle μ < 90 ^o between the mirrors. What is the angle between the incoming and outgoing rays in this case (limited to cases where only two reflections occur)?