If the coast-to-coast distance is about 2900 miles, it will take about ...
... (2900 mi)/(186000 mi/s) ≈ 15.6 ms
for the signal to travel coast-to-coast at light speed.
_____
There are time delays due to the amplifiers and repeaters required in the path, and due to the fact that the signals don't actually travel at the speed of light in a wire.
A test of internet speed between Seattle and Washington, DC shows a round-trip time of about 87 ms when traffic is light. Modern communication channels tend to be faster than the telegraph (especially when measured in words per minute).
Answer:
check reason below
Explanation:
death rates decrease due to advanced technologies(better medical institution)
birth rates decrease to high levels of literacy and due to families planning.
I would guess A. If you think of greenhouse gasses in the atmosphere they trap heat in. that is what causes global warming.
The answer is the second
one.
Deforestation of rain and forests and other parts of the world volcanic eruptions and widespread forest fires.
This activity has contributed greatest amount of carbon dioxide into the atmosphere over the past 100 years.
Answer:
The volcano over a mantle hotspot
Explanation:
I say this because lava comes from the grinding of those mantles, which melt rocks and make lava. If the mantles are super active, the lava will more than likely be explosive. Think of this (heat wise) as tea boiling in a kettle. The stove is the mantle, kettle as volcano and water as lava. When the mantles get hot enough they push that heat and pressure into the water, making it boil and when the steam starts to squeal out of the kettle, the volcano has erupted. Hope this helped!
