How much time does it take a pulse of light to travel through 150 m of water?

6.65*10⁻⁷ s

Explanation:

Speed of light in water = Total distance traveled in water/time

c = d/t ... Equation 1

Where c = speed of the light pulse in water, d = distance traveled in water, t = time.

also

c = v/n ... Equation 2

Where v = speed of light in air, n = refractive index of water

Substituting equation 2 into equation 1

v/n = d/t

making t the subject of the equation,

t = nd/v ... Equation 3

Given: 150 m.

Constant: n = 1.33, v = 3.0*10⁸ m/s

Substitute into equation 3

t = 1.33 (150) / 3.0*10⁸

t = 6.65*10⁻⁷ seconds.

Hence the time = 6.65*10⁻⁷ s