A light ray I is incident on a plane mirror M. The mirror is rotated in the direction as shown in the figure by an arrow at frequency π 9 rev.per sec. The light reflected by the mirror is received o

Question

A light ray I is incident on a plane mirror M. The mirror is rotated in the direction as shown in the figure by an arrow at frequency π 9 ​ rev.per sec. The light reflected by the mirror is received on the wall W at a distance 10 m from the axis of rotation. When the angle of incidence becomes 37° the speed of the spot (a point) on the wall is (in m/s) :

TestHub · Accepted Answer

The mirror rotates at ω = 2 π × π 9 ​ = 18 rad / s , so the reflected ray turns at 2 ω = 36 rad / s . Spot speed on the wall: v = s i n 2 3 7 ∘ 2 ω D ​ with D = 10 m . v = 0.36 36 × 10 ​ = 1000 m / s Answer: 1000.00

Physics - Geometrical Optics Question with Solution | TestHub

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