A boy walks away from a plane mirror at a speed of 3 ms-1 in a direction normal to the surface of the mirror. At what speed is his image approaching him?

  • A 8 9.0ms-1
  • B 6.0ms-1
  • C 4.5ms-1
  • D 1.5ms-1
  • E 0.0ms-1
waec 1996physics

The correct answer is B. 6.0ms-1

Velocity of image w.r.t boy = velocity of object - velocity of image

velocity w.r.t to boy = v - (-v)

=3.0 - (-3.0)

The image velocity is 6 m/s towards the boy.

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