He proposed the theory of Continental Drift. He believed that all of the continents were once joined together in a super continent he called Pangea (not sure if that's spelled right I studied this awhile ago). He proved this by showing similarities in fossils in completely different continents and showing how well the continents could fit together.
Answer:
As you may know, each element has a "fixed" number of protons and electrons.
These electrons live in elliptical orbits around the nucleus, called valence levels or energy levels.
We know that as further away are the orbits from the nucleus, the more energy has the electrons in it. (And those energies are fixed)
Now, when an electron jumps from a level to another, there is also a jump in energy, and that jump depends only on the levels, then the jump in energy is fixed.
Particularly, when an electron jumps from a more energetic level to a less energetic one, that change in energy must be compensated in some way, and that way is by radiating a photon whose energy is exactly the same as the energy of the jump.
And the energy of a photon is related to the wavelength of the photon, then we can conclude that for a given element, the possible jumps of energy levels are known, meaning that the possible "jumps in energy" are known, which means that the wavelengths of the radiated photons also are known. Then by looking at the colors of the bands (whose depend on the wavelength of the radiated photons) we can know almost exactly what elements are radiating them.
Answer: The first one
Explanation: I think it's the first one because it says what is the "least" gravitational potential energy story between the prairie dog and Earth that said resting in its borrow is using less energy
Answer:

Explanation:
Change in velocity considering the x component will be
Final velocity-Initial velocity

Change in velocity considering the y component will be
Final velocity-Initial velocity

Resultant change in velocity
Acceleration= change in velocity per unit time hence

A pot of soup because metal is a better conductor of heat and it stores more heat as well. thermal energy is heat energy.