Question

13. A particle moves perpendicularly towards a plane mirror with a constant speed of 4 cmls. What
is the speed of the image observed by an observer moving with 2 cm/s along the same direction?
Mirror is also moving with a speed of 10 cm/s in the opposite direction,
(All speeds are with respect to ground frame of reference)
(a) 4 cm/s
(b) 12 cm/s
(c) 14 cm/s
(d) 26 cmls​

Answer 1

Thus the speed of the image observed by an observer is 26 cm/s.

Explanation:

• Speed of particle = 4 m/s
• Observed speed of image = 2 m/s
• Image speed = 14 m/s
• Speed of mirror = 10 cm/s

10 + 14 = 24 m/s

SIo = 24 + 2 = 26 cm/ s

Thus the speed of the image observed by an observer is 26 cm/s.