Question

Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass?

Speed of light in vacuum is $\sf{3×10^8}$ m/s

• [tex]\bf{No\:Spamming}​

Answer 1

Answer: Given parameters

Speed of light in vacuum (c) = 3 × 108 ms-1

Refractive index of glass (ng) = 1.50

Refractive index of a medium  = Speed of light in vacuum/Speed of light in the medium

Refractive index of glass = Speed of light in vacuum/Speed of light in the glass

Speed of light in the glass (v) = Speed of light in vacuum/ Refractive index of glass

v = c/ng

v = (3 × 108)/1.50

v = 2 × 108 ms-1

Hope it helps uh cheerio..

Answer 2

$\huge{\underline{\underline{\bf \: Given}}}$

• refractive index if glass = 1.5
• speed of light in vacuum = 3×10⁸ m/s

$\huge{\underline{\underline{\bf \: To \: Find}}}$

• Speed of light in glass

$\huge{\underline{\underline{\bf \: Formula}}}$

$\longrightarrow$ $\underline{\underline\pink{\boxed{\bf n_{glass} = \frac{c}{v} }}}$

here,

• c = speed of light in air
• v = speed of light in given media

$\huge{\underline{\underline{\bf \: Solution}}}$

$\implies\sf \: n_{glass} = \dfrac{3 \times {10}^{8} }{v} \\ \\\implies\sf \: 1.5 = \dfrac{3 \times {10}^{8} }{v} \\ \\ \implies\sf \: v \: = \frac{\cancel{3} \times {10}^{8} }{\cancel{1.5}} \\ \\ \implies\sf \: v \: = 2 \times {10}^{8}$

hence, our required answer is

$\green{\boxed{\bf Speed\:of\:light\:in\:glass = 2×10⁸m/s}}$