Because gas particles in the air like particles of all fluids are constantly moving and bumping into things, they exert pressure. The pressure exerted by the air in the atmosphere is greater close to Earth's surface and decreases as you go higher above the surface.
<u>Explanation</u>:
- Fill roughly one-third of a cup with water. Then, cover the mouth of the cup completely with a flat, hard cardboard. Using your hand to keep it in place, turn the cup upside down. When you remove your hand, the the cardboard stays in place.
-
One would expect that due to gravity, the water will fall, and even the cardboard will. However, it does not, which means that something must be applying an upward force on the cardboard. This is nothing other than air pressure, which applies a force across the surface of the cardboard in an upward direction.
- Thus we can demonstrate that air exerts pressure, because otherwise, the water would have fallen.
I believe answer the only correct answer is A. Only from thinking of how gravity works with the natural world around us. Plus answer d doesnt makes sense, and c is false. And lastly if you throw a bowling ball and soccer ball over a bridge at the same time, they will fall at the same rate, only thing that would delay them is if one had more air resistance than the other.
It does make sound, just because there are no receptors does not mean that an object does not make sound. For example, whales communicate ona frequency higher then our ears can hear, however, we know that they still make sound. Another example is thunder; If you were far away to see thunder but not hear it, does it make sound? It does. Objects make sound by vibrating, there is no connection to sound and the presence of a receptor.
The gravitational forces between two objects decrease when the objects
move farther apart.
This is a big part of the reason why our bodies are attracted toward the
Earth more strongly than they are toward Jupiter.
Potassium belongs to group IA of the elements. This means that it will give up one of its electrons to form the cation K+. Opposite to that is bromine in which it accepts one electrons to form the anion Br-. The binding of these elements will form KBr and is formed from transfer of electron from one element to the other. This is the mechanism of ionic bond formation.
