Question 344: Ray Optics

Question

A small coin is resting on the bottom of a beaker filled with liquid . A ray of light from the coin travels upto the surface of the liquid and moves along its surface. How fast is the light travelling in the liquid ?

Accepted Answer

As $${1 \over \mu } = {{\sin i} \over {\sin 90^\circ }}$$
$$ \Rightarrow $$ $$\mu $$ = $${1 \over {\sin i}}$$ = $${5 \over 3}$$
Speed, v = $${c \over \mu }$$ = $${{3 	imes {{10}^8}} \over {5/3}}$$ = 1.8 $$ 	imes $$ 10
8
m/s

Answer

2.4 $$ 	imes $$ 10
8
m/s

Answer

3.0 $$ 	imes $$ 10
8
m/s

Answer

1.2 $$ 	imes $$ 10
8
m/s

Answer

1.8 $$ 	imes $$ 10
8
m/s

Ray Optics

A small coin is resting on the bottom of a beaker filled with liquid . A ray of light from the coin travels upto the surface of the liquid and moves along its surface. How fast is the light travelling in the liquid ?

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