A cubical room is formed with six plane mirrors. An insect moves along the diagonal of the floor with uniform speed. the velocities of its images in two adjacent walls are 20x2^1/2 cm/s. then the velocity of the image formed by the roofs.

please solve with explaination

Dear student,

The velocity of the image formed by the roofs=root 2 times 20x2^1/2

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Askiitians Expert

Sagar Singh

B.Tech, IIT Delhi

let Vx and Vy be the components of velocity of insect. we have Vx=Vy,components of image velocity on adjacent walls are Vx and 2Vy, thus

(20x2^1/2)²=Vx²+Vy²=5Vx²=800, Vx²=160, components of image velocity on roof are Vx and Vy,

V²=Vx²+Vy²=2Vx²=320, V=320^1/2=8√5 cm/s