A concave mirror of radius 40 cm lies on a horizontla tale and wateis filled in it up t a heightof 5.00 cm. A small dust particle floats on the water surface at a point P vertically above tge pointof contact of the miror with the table. Locate the image of the dust particle as seen from a point directly above it. tEh refractie index of water is 1.33.

Explanation

The dust particle is in water.
Image by concave mirror
`mu=-5 cm,,f=-20 cm,v=?`
`1/v+1/u=1/f rArr 1/v+1/(-5)=1/(-20)`
`rArr 1/v=1/5-1/20=3/20rArrv=20/3cm`
The image of P is formed at I.
Image by refraction After reflection direction of incident rays is reversed. I serves as an object
`mu_(1)=2/3,u=-(5+20/3)=-35/3`cm
`mu_(2)=1,v=?`
`(mu_(2))/v-(mu_(1))/u=0rArr1/v-(2//3)/((-35//3))rArrv=-35/2=-17.5 cm`
Final image is formed at I'. PI=17.5 cm