1. ## Time delay question?

Hey guys i didn't know how to do this question and figure out the answer, can you help me?

Internet and telephone communications across long distances involve noticeable time delays. The delay is caused by switching latencies and distance. Electrical signals travelling on wires and light signals traveling through fibre-optic cable both travel at about 2/3 of the speed of light. Radio waves traveling through air and space travel at about the speed of light. Using these facts, calculate the following:

a) The time delay for a signal to get across the world (say from here to Egypt) traveling through cables

b) The time delay for a signal traveling across the world via satellite

2. Originally Posted by Cockchestner007
Hey guys i didn't know how to do this question and figure out the answer, can you help me?

Internet and telephone communications across long distances involve noticeable time delays. The delay is caused by switching latencies and distance. Electrical signals travelling on wires and light signals traveling through fibre-optic cable both travel at about 2/3 of the speed of light. Radio waves traveling through air and space travel at about the speed of light. Using these facts, calculate the following:

a) The time delay for a signal to get across the world (say from here to Egypt) traveling through cables

b) The time delay for a signal traveling across the world via satellite
You need the path length d, then the delay id d/v, where v is the appropriate propagation speed. This is OK for (a) as we know the distance (half the circumference of the Earth, which we can look up). In the case of (b) we do not know the path length and will have to estimate it by guessing at the relative positions of the satellite/s

CB