Answer: Humans are moving more Carbon into the atmosphere with things like fossil fuels. We are also cutting down trees and other plants that actually take carbon away from our atmosphere through photosynthesis and adding oxygen. This is causing the carbon to get stuck in the atmosphere and contaminating our air.
Explanation:
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:
C.
Explanation:
Because the Earth is tilted on its axis not every part of the Earth gets the same amount of sunlight. This is the reason that we have seasons and why not every part of Earth has the same season at the same time or with the same intensity. People usually think this is because the earth moves away or closer to the sun but it is actually because of the tilt.
Answer:
Dams help in preventing floods. They catch extra water so that it doesn't run wild downstream. Dam operators can let water out through the dam when needed. The first upstream flood control dam was built in 1948, Cloud Creek Dam in Oklahoma.
People build reservoirs because the amount of water in a river varies over time. During very rainy times or when mountain snow is melting, the water in a river rises and sometimes overflows its banks. By limiting the amount of water allowed to continue downriver, reservoirs help control flooding.
Explanation:
