A 6,000-km undersea glass fiber phone line crosses the Atlantic ocean connecting the US and France. (a) How long does it take for a message to transverse this link? (b) How long does it take for a message to travel from US to France by using a satellite link? The satellite is stationed about 22,000 miles above the earth between the US and France. (c) Will two people having a conversation across these two different links notice the travel delays?

Explanation:

Message will travel through the fibre at the speed of 3 x 10⁸ m /s which is also the speed of light .

a ) Time for a message to travel from US to France by using glass fibre  link

time  = distance / speed

= 6000 x 1000 / 3 x 10⁸

= .02 s .

b )

22000 miles = 1.6 x 22000

= 35200 km

Time for a message to travel from US to France by using a satellite link

time = distance / velocity

 distance = 2 x √ ( 35200² + 3000² )

=  2 x 35327 km

= .7 x 10⁸ m .

time = .7 x 10⁸ / 3 x 10⁸

= .233 s

c )

Difference of time = .233 - .02

= .213 which is more than 1/6 s for which effect of hearing stays in the brain , which is called persistence of vision .  So they will be heard as different sounds.

like poles repel so keep pushing north to north and repels funny to see this