A fish under water observes a freely falling stone in air. If The refracting index of water is 4/3 what is the apparent acceleration of the stone as observed by the fish. Please give a detailed explanation.

Under normal circumstances, the acceleration is 9.8m/s2 `because it`s a free fall.In water, the velocity of light reduces by 1.33 times as the refractive index of water is 4/3. So the apparent acceleration would be 1.3 times less or 9.8/1.3 = 7.36m/s2