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36 votes
36 votes
Kyle lays a mirror flat on the floor and aims a laser at the mirror. The laser beam reflects off the mirror and strikes an adjacent wall. The plane of the incident and reflected beams is perpendicular to the wall. The beam from the laser strikes the mirror at a distance a=60.1 cm from the wall. The reflected beam strikes the wall at a height b=31.3 cmabove the surface of the mirror.Find the angle of incidence θiat which the laser beam strikes the mirror.

User DorianOlympia
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1 Answer

26 votes
26 votes

Answer:

62.5 °

Step-by-step explanation:

✓From law of reflection, angle of incidence equals angles of reflection .

✓the angle between the reflected ray can be determined using trigonometry, we know that

horizontal distance x =60.1 cm

the vertical distance is y =31.3

Then

tan( θ) =( y / x)

If we substitute the values we have,

tan θ = 31.3 / 60.1

θ = tan⁻¹ (0.5208)

θ = 27.5°

This angle is been measured using x-axis (horizontal)BBut in optics we can measured with respect to y-axis then angle becomes

θ = 90 - 27.5

θr = 62.5 °

θr = θi= 62.5°

the angle of incidence θiat which the laser beam strikes the mirror is 62.5°

User Shnatsel
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