Question

light enters from air into a glass plate having refractive index 1.50. What is the speed of light in glass????​

Answer 1

Explanation:

As we know,

• Speed of light in Vacuum = 3 × 10^8 m/s

$Refractive \: index \: of \: a \: medium = \\ \bf\frac{Speed\:of\:light\:in\:vaccum}{Speed\:of\:light\:in\:Medium} \\ \\ Speed\:of\:light\:in\:Medium = \\ \\ \: \bf\frac{Speed\:of\:light\:in\:vaccum}{Refractive \: index \: of \: a \: medium } \\ \\ = \frac{3 \times {10}^{8} }{1.5} \\ \\ = 2 \times {10}^{8} \: m{s}^{ - 1}$

Answer 2

Answer:

$\sf\underline{ \rm \red{2 \times {10}^{8} m/s , \: }}$

Explanation:

$\sf{ \rm {refractive \: index = \frac{speed \: of \: light \: in \: air}{speed \: of \: light \: in \: glass} }}$

$\sf{ \rm {so, \: 1.50 = \frac{3 \times {10}^{8} }{speed \: of \: light \: in \: glass }}} \\ \\ \: \therefore \: \sf\underline{ \rm \red{speed \: of \: light \: in \: glass \: }} = \frac{3 \times {10}^{8} }{1.50} m/s \\ \\ = 2 \times {10}^{8} \sf\underline{ \rm {m/s}}$