Question

In a pond a fish at rest sees a bird diving vertically towards water at the rate of 3m/s vertically above the fish If the refractive index of water is 4/3 .What is the actual speed of the bird

Answer 1

Here is an explaination (calculus) of a more elaborate problem, take a look: https://www.zigya.com/study/book?class=12&board=tbse&subject=Physics&book=Physics+Part+II&chapter=Ray+Optics+and+Optical+Instruments&q_type=&q_topic=Refraction+at+Spherical+Surfaces+and+by+Lenses&q_category=&question_id=PHEN12057601

Answer 2

2.25