Answer:
I think the answer is a because boiling water cleans it
1. One
2. Oohm
Hope this helps
B. An apple about to fall from a tree branch
This is because potential energy is the energy before its actuall motion, or before kinetic energy (energy in motion). And the apple ABOUT TO FALL mentions a gravitational example.
The total amount of water on earth <u>remains the same</u>.
<u>Option: A</u>
<u>Explanation:</u>
The quantity of water on Earth remains the same now as it was in the Olden days. All water which is consumed by living things continue to be as part of the Earth's total water content.
The total amount is not exactly constant, as there are two fluxes of water between Earth and the rest of the solar system. There is a steady rain of water-bearing meteoroids hitting the planet, which slowly increases the amount of water. At the same time, molecules of water often dissociate in the upper atmosphere into hydrogen and oxygen due to ultraviolet light from the sun. Some of the hydrogen atoms have enough energy to escape from Earth’s gravitational field, and so are lost. This slowly decreases the amount of water.
In addition, tectonic plate subduction is constantly carrying water down into Earth’s mantle, and volcanoes are constantly spewing water out onto the surface again. The balance between the two processes can change considerably over time.
But all of these actions are meager compared to the total quantity of water on our planet, and two of them are in the opposite direction of the other two. So the overall change is insignificant, even when considered over long spans of geologic time.
Answer:
We understand that two like poles of magnet repel each other. Maglev train is based on the same concept. The train levitates above the tracks because of repulsion between one set of magnets. One set of magnets lifts the train upwards causing it to levitate or float above tracks and other set of magnets causes it to move forward. This method enables less consumption of energy as loss of energy due to friction is negligible and also, high speed can be achieved.
