Physics - Geometrical Optics Question with Solution | TestHub
A bird in air is diving vertically over a tank with speed 6 m/s and a fish in the tank is rising upward along the same line with speed 4 m/sec. Base of tank is silvered. [Take ]
List - I | List - II |
|---|---|
(I) Speed of the image of fish as seen by bird directly | (P) |
(II) Speed of image of fish formed after reflection from the mirror as seen by bird | (Q) 4 m/s |
(III) Speed of image of bird relative to fish looking upwards | (R) |
(IV) Speed of image of bird relative to the fish looking downward in the mirror | (S) 9 m/s |
(T) 12 m/s |
Options:
Answer:
Solution:
Direct view: the fish's image rises at m/s; relative to the diving bird m/s (I → S).
After reflection at the silvered base, the image recedes at apparent speed m/s (II → P).
The bird's image apparent speed seen from water is m/s; relative to the rising fish m/s (III → T).
In the mirror the bird's image approaches at 8 m/s while the fish rises at 4 m/s: relative m/s (IV → Q). Option (B).
