Light travels in air with speed and in water with speed

PHYSICS · Single correct · A Level · Physics · Waves · Waves

Problem

Light travels in air with speed

v_1=3.00\times10^{8}\,\text{m}\,\text{s}^{-1}

and in water with speed

v_2=2.25\times10^{8}\,\text{m}\,\text{s}^{-1}

. A plane wavefront is incident from air onto the water surface at an angle of

60^{\circ}

to the normal. Find the approximate angle of refraction in water. (a)

45^{\circ}

(b)

36^{\circ}

(c)

41^{\circ}

(d)

22^{\circ}