Question

An object placed in front of a plane mirror is slowly moved towards the mirror at a rate of 1.5 cm s-¹. At what rate the object is approaching is image formed in the mirror? please answer it​

Answer 1

Answer:

it can be solved easily with help of vector method. Let initially, mirror is placed at origin. and object is negative direction of x -axis. then,

object distance from the plane mirror,  

mirror moves towards the object,  

we know,

in case of plane mirror,

here,  means position of object with respect to mirror and  means position of image with respect to mirror,

or,  

or, -20i - (-2i) =-xi - 2i

or, xi = 24i

but original position of image is 20i [ just opposite to position of image ]

hence, distance between the positions of the original and final image seen in the mirror is (24 - 20) = 4cm