Question

Light travels at 3.0 × 108 m/s in a vacuum. Use the index of refraction for water to determine the speed of light in water. Round your answer to the nearest tenth.

Answer 1

The answer is 2.3. I just answered this question and got it right.

Answer 2

Answer: The velocity of light in water is 225056264.1 m/s.

Explanation:

To calculate the speed of light in medium (water), we use the formula:

$\eta=\frac{c}{v}$

where,

$\eta$ = index of refraction of water = 1.333

c = speed of light in vacuum = $3\times 10^8m/s$

v = speed of light in water = ?m/s

Putting values in above equation, we get:

$1.333=\frac{3\times 10^8}{v}\\\\v=2.2505626406\times 10^8m/s$

To round the speed of light in water to the nearest tenth place, we will multiply the exponent with the answer and then round off the tenth place.

$2.2505626406\times 10^8=225056264.06$

Rounding 0.06 to 1 because 6 is more than 5, we get:

$\Rightarrow 225056264.1m/s$

Hence, the velocity of light in water is 225056264.1 m/s.