Question

when light passes through water, it’s velocity is reduced by 25%. If the speed of light in a vacuum is 1.86 x 10^5 miles per second, at what velocity does it travel through water? write your answer in scientific notation.

Answer 1

Answer:

The speed of light in water is 1.395 × $10^{5}$ miles per hour .

Step-by-step explanation:

Given as :

The speed of light in a vacuum = $v_1$ = 1.86 × $10^{5}$ miles per sec

Let The speed of light in water = $v_2$ miles per hour

When light passes through water, its speed reduced by 25%

So,  $v_2$ = 1.86 × $10^{5}$ miles per sec - 25% of $v_1$

Or, $v_2$ = 1.86 × $10^{5}$ miles per sec - 25% ×  1.86 × $10^{5}$ miles per sec

Or, $v_2$ = 1.86 × $10^{5}$ miles per sec ×( 1 - $\dfrac{25}{100}$)

Or, $v_2$ = 1.86 × $10^{5}$ miles per sec × $\dfrac{75}{100}$

Or, $v_2$ = 1.86 × $10^{5}$ × 0.75

∴  $v_2$ = 1.395 × $10^{5}$  miles per hour

So, The speed of light in water = $v_2$ = 1.395 × $10^{5}$ miles per hour

Hence, The speed of light in water is 1.395 × $10^{5}$ miles per hour . Answer