Answer:
Option (4)
Explanation:
Seismic P and S waves are generated during an earthquake that has the potential to propagate through the interior of the earth. P waves are also known as the primary waves and they move in a compression and extension way in their direction of propagation. S waves are shear waves. This P waves travel faster than the S waves and can travel in both solid as well as in liquid. Whereas the S wave can travel only through solids. They get absorbed when they reach the core-mantle boundary. These two waves are helpful in determining the epicenter of an earthquake by recording the arrival of these waves.
Hence, the correct answer is option (4).
Answer:
Hydrogen in the core of the star is converted to helium by nuclear fusion. When the hydrogen supply in the core begins to run out, and the star is no longer generating heat by fusion, the core becomes unstable and contracts.
Explanation:
Most definatley! They are so real!
Uniformitarianism- the theory that changes in the earths crust during geological history have resulted from the action of continuous and uniform processes