Afish is 1.2 m beneath the surface of a still pond of water. at what maximum angle can the fish look toward the surface (measured with respect to the normal to the surface) in order to see a fisherman sitting on a distant bank? (for water, n = 1.333)

49°

Explanation:

Depth at which the fish is found= 1.2 m

refractive index for water, n= 1.333

Using snell's law we can write

i and r are angle of incidence and angle of refraction respectively

Here, r= 90°

put value of n and r to get i

sin 90= 1  and

implies that i= 49°

hence, the maximum angle of incidence i= 49°

we need to know the time interval during which the force acts. impulse of force = momentum change