A bird flies down vertically towards a water surface. To a fish inside

1.	A bird flies down vertically towards a water surface. To a fish inside the water, vertically below the bird, the bird will appear to (a) be farther away than its actual distance (b) be closer than its actual distance (c) move faster than its actual speed (d) move slower than its actual speed
Answer» Correct Answer is: (a, c) Let x = height of the bird above the water surface. For light travelling from the bird to the fish, μ₁ = 1, μ₂ = μ (refractive index of water), u = -x. μ/v = 1/-x or v = -μx or \|v\| = μx > x. Speed of bird = x , apparent speed of bird = \|v\| = μx.

A bird flies down vertically towards a water surface. To a fish inside the water, vertically below the bird, the bird will appear to (a) be farther away than its actual distance (b) be closer than its actual distance (c) move faster than its actual speed (d) move slower than its actual speed

Answer»

Correct Answer is: (a, c)

Let x = height of the bird above the water surface.

For light travelling from the bird to the fish,

μ₁ = 1, μ₂ = μ (refractive index of water), u = -x.

μ/v = 1/-x

or v = -μx

or |v| = μx > x.

Speed of bird = x , apparent speed of bird = |v| = μx.

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A bird flies down vertically towards a water surface. To a fish inside the water, vertically below the bird, the bird will appear to (a) be farther away than its actual distance (b) be closer than its actual distance (c) move faster than its actual speed (d) move slower than its actual speed

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