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.
A is right because I took the test
Higher pitched sounds produce waves which are closer together than for lower pitched sounds. A smaller triangle or cymbal will make a relatively higher pitch note
when wave propagate through the medium the medium particles have two type of possible motions
1) Transverse Waves : here medium particles will move perpendicular to wave propagation and they pull and push perpendicular to the length
2) Longitudinal wave : here medium particles will move to and fro along the length of the medium and the medium particles will push and pull together along the length of the string.
So here in two types of wave motion it will depends on the medium type as well as it will depend on the source how is wave produced.
So the given type of wave in which particles push together and pull apart the wave must be longitudinal wave.