If you want to delay a pulse of light in a laser experiment, you can send the light through a long coil of fiber optic cable. Light travels somewhat slower in the glass core of a fiber than it does in vacuum. We will approximate the speed of light in the fiber as 2.04 x 108 m/s. What length of fiber (in meters) should you use if you want to delay the arrival of light by 557 ns

d = 113.6 m

Explanation:

For this exercise, the first thing we must notice is that the speed of the laser beam in the fiber is constant, so we can use the uniform motion relationships to find the necessary distance

          v = d / t

let's reduce to SI units

         t = 557 ns = 557 10⁻⁹ s

         d = v t

         d = 2.04 10⁸ 557 10⁻⁹

         d = 1.136 102 m

         d = 113.6 m

This is the distance of the fiber for the laser to arrive with the desired delay

trig 15.3 cos

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day