An object kept on the principle axis is moving in the same direction as that of mirror is `10m//s` and `40//13m//s`. Radius of the curvature of the mirror is 20 cm. What should be the distance of object from the mirror at this instant so that the image is stationary?

Options

A. 45 cm
B. 37.5 cm
C. 25 cm
D. 15 cm

Answer

C

Explanation

`vecV_(im)=(v^(2))/(u^(2))vecv_(om)`
`0-(40)/(13)=-((-10)/(-10+x))^(2)(10-(40)/(13))`
`=(-10)/(-10+x)=+-(2)/(3)`
`x=25,-5cm`
Object is infront of mirror
Hence `25cm`