Answer:
Nitrogen and oxygen are by far the most common; dry air is composed of about 78% nitrogen (N2) and about 21% oxygen (O2). Argon, carbon dioxide (CO2), and many other gases are also present in much lower amounts; each makes up less than 1% of the atmosphere's mixture of gases.
I. Positive acceleration increases velocity. Negative acceleration decreases velocity. runner A sped up until the finish line and then slowed to a stop.
ii. Zero a acceleration implies a constant, unchanging velocity not a zero velocity. runner B achieved some velocity prior to 8s and is moving and must slow down to reach a stop.
iii. None. No aspects of this reasoning are correct. Everything she says is wrong. See iv for what/why.
iv. The sign on acceleration denotes the direction of *change in velocity* not change in direction. The sign on velocity can denote change in direction but only “forward” or “reverse” along a particular path. Cardinal direction is not indicated, generally, by the sign on velocity. It may correspond to North/South situationally but it is not an built-in feature of velocity and its sign. For example, if you are traveling with positive velocity and turn left to continue your journey you still have a positive velocity in the new direction. In fact, if you turn left again, traveling in the opposite direction as the one you started with your velocity would still be positive… in the new direction. The velocity relative to original direction could be said to be negative but that would be a confusing way to describe a journey. Maybe if you stopped the vehicle and moved in reverse, you could meaningfully say velocity was negative.
Answer:
4) Isaac Newton was the first scientist to propose the idea that gravity increases distance between objects decrease
Explanation:
1 - Kepler may have inspired most of Newton's propositions, but there is no record of collaborating on the theory of universal gravitation.
2 - The universal gravitation theory resemble the works of other great scientists, but Newton was indeed the first to propose this idea of gravitation
3 - On the contrary, these scientists have shared concepts, with differences in accuracy that supersede each other to be accepted by the community (i.e: Einstein being at the forefront despite sharing some ideas with Newton)
Wind is the result of convection currents. :)
The best system to talk about would be a galaxy system. Energy does not enter the galaxy, but it does "recycle" its energy. For instance, when the life of a star comes to its end, it can go super nova. and all the energy from that star is then released back into the galaxy to form nebula's and then eventually into other stars. The energy inside of a galaxy can change frequently. It can be in the form of heat from a star, or it can change into gamma radiation from an explosion. Gases like helium and hydrogen come together and form a ball of gas creating the heat. Then the heat is dispersed leaving different types of radiation like gamma, ultra-violet, microwave, and infrared. Energy can leave a system by the local black holes. Black holes with shoot out Hawking radiation is when the black hole disperses its own energy out into space, also known as Black Hole Evaporation<span>. The energy from that black hole is then dispersed into the rest of the universe or possibly back into the galaxy from which it came from. </span>
