A) 251.2 m/s
B) 261.2m/s
C) .271.2m/s
D) 241.2m/s
Correct Answer: A
Solution :
Key Idea: One revolution covers 2 n radians. The relation between angular velocity (co) and linear velocity (v) is \[v=r\,\omega \] where r is radius of path. Angular velocity of mirror \[=4\pi \] rad/s. Angular velocity of reflected ray \[=2\times 4\,\pi =8\,\pi \] rad/s \[\therefore \] \[v=10\times 8\,\pi =80\times 3.14=251.2\,m/s\].You need to login to perform this action.
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