Answer:
A. nuclear fusion reactions
C. it's still hot from the big bang
Explanation:
The inside of the earth is hot due to some reasons. This heat provides the internal energy the drives processes within the earth interior. Here are some of the ways in which the heat has accumulated:
- Nuclear reactions within the earth interior by fusion and other radioactive processes releases a large amount of heat.
- Some heat accreted during the early formation of the earth and has not been lost till this day.
- Heating due to friction
These are some of the sources of the earth's internal heat.
Explanation :
According to astronomers, the whole universe is started with a giant explosion called as Big Bang. Big Bang theory shows that the universe is extended from high density state.
There are some evidence for big bang as :
(1) There are some red shifts of different galaxies which means that the universe is expanding.
(2) Due to the expanding of universe, some of the new elements are created like hydrogen, deuterium etc.
(3) Microwaves are detected by orbiting detectors.
All this parameters shows that big bang theory was correct.
Answer:
16.7 s
Explanation:
T= <u>Vf - Vo</u> a= <u>F</u>
a m
4,500 / 3000 = 1.5 (a)
30 - 5 / 1.5(a) = 16.7 s
Frequency represents the number of complete oscillations in one second. it is measured in Hertz (Hz). Electromagnetic waves are waves which do not require a material media for transmission. They travel with a speed of light.
The speed (m/s) of a wave is given by frequency (Hz) × Wavelength (m)
Speed is 300,000 km/sec or 300,000,000 m/s and the wavelength is 300,000 km or 300,000,000 m.
Frequency = speed÷ wavelength
= 300000000 ÷ 300000000 = 1
Therefore, the frequency of the wave is 1Hz
