Physicist Fish
A fish in the aquarium is approaching the left wall of the aquarium at the speed of
while a ball is approaching the same wall .The fish observes the ball to be coming towards it at the speed of
. Find the actual speed of the ball .
Take the refractive index of water as .
The answer is 4.
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1 solution
If the fish was stationary, it would see the ball come at it with a speed of 8 - 3 = 5 m/s. A body in water sees something(in the air) come at it at a speed of u(water)×actual speed of that something. Thus, 5x/4 = 5, therefore x = 4 .