1. The problem statement, all variables and given/known data As shown in the figure, a man is running towards left with constant velocity of 7 m/s. Also, a flat vertical mirror is moved to the right with constant velocity of 9 m/s. Calculate the relative velocity between the man and his image. Express your answer in meter/second. Figure - 2. Relevant equations 3. The attempt at a solution Since man is running to the left with velocity 7 then the image also must move right at 7 m/s. Also since the mirror is also moving , the total velocity of the image is 16 m/s towards right. So the relative velocity between the man and image should be 16+7= 23m/s . But the answer is incorrect . Please explain.