rotations and revolutions. When an object turns around an internal axis (like the Earth turns around its axis) it is called a rotation. When an object circles an external axis (like the Earth circles the sun) it is called a revolution.
Radio waves are electromagnetic waves and as such travel at the speed of light. Waves emitted a century ago would be 100 hundred light years away. A light year is the distance light travels in one year. In one year light travels about 5.9 trillion miles. therefore the waves traveled about 590 trillion miles in a century.
Answer:
time taken for 25% Phlebotinum and 75% Dilithium is 168 million years
Explanation:
radioactive isotope of Phlebotinum decays into Dilithium.
time taken to half life takes = 42 million years
half life means that the Phlebotinum is 50% and Dilithium is also 50%
and now it is given that Phlebotinum is 25% and Dilithium is 75%
hence this condition will come after two half lives.
for one half life it takes 42 million years
and for second half life time becomes 4 times of first half life
time for 25% Phlebotinum and 75% Dilithium is = 4 × 42
= 168 million years.
hence time taken for 25% Phlebotinum and 75% Dilithium is 168 million years
Answer:Nonrenewable energy resources, like coal, nuclear, oil, and natural gas, are available in limited supplies. This is usually due to the long time it takes for them to be replenished.
Renewable resources are replenished naturally and over relatively short periods of time.
Explanation:
The length of daylight and nighttime are of equal length on an equinox because the center of the sun spends a roughly equal amount of time above and below the horizon at every location on the Earth.