Example 9 4 Suppose while sitting in a parked car you notice
Last updated: 6/30/2023
Example 9 4 Suppose while sitting in a parked car you notice a Jogger approaching towards you in the side view mirror of R 2 m If the jogger is running at a speed of 5 m s how fast the image of the Jogger appear to move when the jogger is a 39 m b 29 m c 19 m and d 9 m away Solution From the mirror equation Eq 9 7 we get fu u f For convex mirror since R 2 m 1 m Then 39 x1 39 39 1 40 for u 39 m U Since the jogger moves at a constant speed of 5 m s after 1 s the position of the image v for u 39 5 34 is 34 35 m The shift in the position of image in 1 s is 39 34 1365 1360 5 1 40 35 1400 1400 280 Therefore the average speed of the image when the jogger is between 39 m and 34 m from the mirror is 1 280 m s Similarly it can be seen that for u 29 m 19 m and 9 m the speed with which the image appears to move is 1 10 100 m m 1 150 Although the jogger has been moving with a constant speed the speed of his her image appears to increase substantially as he she moves closer to the mirror This phenomenon can be noticed by any person sitting in a stationary car or a bus In caso of simil 1 ms ms and ms respectively 60