C. A mechanical wave generally travels faster in gases than liquids.
The correct answer to the question is : Transverse wave.
EXPLANATION :
Before going to answer this question, first we have to understand the longitudinal and transverse wave.
LONGITUDINAL WAVE : A longitudinal wave is a mechanical wave in which the direction of vibration of particles is parallel to the direction of wave propagation. It moves in the form of compression and rarefaction.
For instance, sound wave.
TRANSVERSE WAVE : A transverse wave is a mechanical wave in which the direction of vibration of particles is perpendicular to the direction of wave propagation. It moves in the form of crests and troughs.
For instance, the wave created in a pond when a stone is dropped into it.
Hence, the correct answer of this question is transverse wave.
Answer:
Hey
Your answer would be Radioactive Decay and Heat of formation.
When earth first formed it was very violant. Some planetary scientists believe that the moon was created from a collision involving earth and Thea (a theoretical dwarf planet). these collisions that have formed earth heated it so much that it is still hot from them.
Radioactivce decay is another major fource of internal heat for earth.