A particle moves perpendicularly towards a plane mirror with constant speed 4 cm/sec. what will be the speed of image observed by an observer moving with 2 cm/sec along the same direction? Mirror is also moving with a speed 10 cm/sec in the opposite direction. (all speeds are with respect to ground frame)

26cm/s

$V_{I,m} = - V_{O,m} $

$ V_I = 2V_m - V_o = 20 - (-4) = 24cm/s$

$ \text{Since observer is moving so } V = 24+ 2 = 26cm/s$