Energy

Question: energy....? when going down a hill, is potential energy converted to kinetic energy or is that the other way around? and how does conservation of energy relate to roller coasters?

Answer: Rolling down hill is turning potential energy into kinetic energy as you said. Conservation of energy relates to a roller coaster ride. going down a hill gains enough kinetic energy to be able to convert the kinetic energy into the potential energy gained by climbing the next hill. The reason the hills can not be the same height is that friction converts some of the energy into heat.

Question: EnERGY?????? what can make you extremely HYPER... any foods...any drinks...energy drinks...ANYTHING???? please be specific for long term energy....more than 8 hours

Answer: Sugar and caffeine are going to make you temporarily hyper, and then you'll crash. Best to go with slower acting (i.e. unprocessed) carbs like whole grains and fruits, and add a protein shake. You won't be "hyper", but you'll have sustained fuel.

Question: Energy???? What on the earth is energy? Is it only what we are taught in physics class or is it anything more?

Answer: Physics class is just the begining of the journey, never the destination. Energy is the ability to do work. (standard textbook definitiion). It is also the second largest financial derivative opportunity right now (behind interest rates) -- fianancial definition. It is a battleground for the next presidential election (political definition), and an excuse for not mowing the lawn (relationahip definition). Good place to go is wikipedia... The term Energy (from Latin Energia and Greek Ενεργεια) refers to the ability of a physical system to do mechanical work.[1] It is a fundamental concept pertaining to the ability for action. The energy of a system can be quantified in many interdependent forms, but the total energy of a system is subject to conservation. Energy is not measured as an absolute quantity, but as relative to a reference state or level. For example, a litre of water has more thermal energy when it is warm than when it is cold, and a car in motion has more kinetic energy than when it is at rest. It is important to realize that the selection of a reference state is arbitrary and has no effect on how a physical system operates, but that an informed selection can greatly simplify one's understanding of that system.

Question: ENERGY!!!!!!!!!!!!!!!!!!!!!!!!? Are there any books that have some pretty good detai.s about energy drinks?? It is for my science project at school. thankies!!

Answer: you know, consider me a good book with some pretty good detai.s about energy drinks. i'll tell you about the sperm they deplete and the crash they entail.

Question: ENERgY???? i am very sluggish right now. All ive had to eat today were some fries and coke. (i know, i dont usually eat like this :|) what food can give me aboost?

Answer: Usually meat, pork, or beef

Question: What is the energy conversion that occurs in cellular respiration? Chemical energy in glucose is converted to light energy. Light energy is converted to chemical energy in glucose. Energy in glucose is converted to packets of stored energy in the organism. Packets of stored energy are converted to chemical energy in glucose I need it for school, I'm in Virtual School and iI need it, Thanks.

Answer: chemical energy is converted into heat and electricity

Question: What happen to heat energy after it is released to the atmosphere? According to the conservation of energy, energy is transformed into other forms of energy. In real cases, for example, in engines, not all chemical energy (from the fuel) is converted to kinetic energy (correct me if I'm wrong) because some of the input energy is dissipated as heat energy. So logically, the heat energy is released to the atmosphere. What happens to the heat energy after that?

Answer: The problem is that heat energy is dissipated, i.e. heat energy that is produced spreads out. The radiators in a lecture room produce heat energy. This heat energy dissipates and the surrounding area becomes very slightly warmer etc. This dissipated heat energy cannot be regained in a useful form.

Question: How is energy conserved when a dropped object hits the ground? I know that when an object is held at a particular height above the Earth, it has a quantity of potential energy associated with it, but no kinetic energy. When the object is dropped, it loses potential energy and gains kinetic energy, thereby ensuring that energy is conserved. However, I've never understood what happens when the object finally strikes the ground; at this point, it has no potential and no kinetic energy. I'm sure some of it is released as heat and sound, but that can't account for all the energy, can it?

Answer: If the collision between the object and the ground were perfectly elastic, you would find that the object would bounce back up, from the ground, to the initial height that it was dropped from. However, when the collision is inelastic (like the case you are referring to), energy is dissipated by three means: compression waves generated in the air (sound), deformation of the objects involved in the collision, and some heat release due to friction. Energy is this case (as in every case) is conserved, the problem is that useful energy has been turned into very useless forms of energy - heat, sound, and deformed objects.

Question: What energy changes take place when a ball that is falling through the air reaches its terminal velocity? I know that at terminal velocity, kinetic energy remains constant. I know that potential energy decreases because the height changes and air friction against the ball causing heat but I know that is minimal. I really need to know also, where does all that extra potential energy go because before terminal velocity, I would have said kinetic energy but because this is constant, where does the bulk of the potential energy go. Please correct me if I am wrong.

Answer: The kinetic energy might be constant, but you have to remember that at the point it attains its terminal velocity it is traveling at a great speed. KE is directly proportional to the square of velocity. The heat produced by air friction can not be ignored. There could be other forms of energy transformation taking place, such as sound, light, etc. But the sum of all these different forms of energy would still be equal to the initial potential energy of the ball . teddy boy

Question: What energy exactly does photosynthesis extract from sunlight? Photosynthesis, the biological conversion from light energy to chemical energy... But I thought photons have zero mass (therefore zero energy?), so where is this energy coming from? Does it just refer to the extremely small energy that comes from a photon's momentum?

Answer: Photons have energy even if they dont have mass (rest mass). Both subjects are not directly related. The energy of a photon is calculated as Energy=frecuency*plank constants and is usally measured in electronvolts. The average photon in solar radiation has an energy of 1.5 electronvolts. Again, no mass is required.

Question: Is worldwide energy drilling and mining going at such a pace that will tank energy stocks in the near future? I look at a map of energy production around the world. There are so many mines, so many drill sites pumping oil, so much energy being extracted, competing with solar production etc. Is the energy sector bubbled at the top? It just doesn't make sense to me otherwise! Unbelieveable energy mining and drilling! Unbelievable!

Answer: There are more drillings than ever before but less is oil is being extracted. Scary but its going to get worse. Here is the link: http://www.commodityonline.com/news/topstory/newsdetails.php?id=6839

Question: What happens to black holes how much energy do they contain? What happens to all the energy that black holes consume? They must contain a massive amount of energy seeing that they eat up all the light and matter and energy that gets to close. What happens to this energy? Does the energy eventually cause the black hole to cease to exist? The reason a black hole is created is when the star starts to fuse iron and that takes energy. This in turn causes it to collapse in on it's self as it gobbles up the energy. If over millions or billions of years the Black Hole eats up enough energy will that energy destroy the singularity?

Answer: Black holes evaporate! When a black hole is not Active (meaning they are not consuming stars and other stellar objects) the black hole actually releases more energy than is being consumed. This is called Hawking Radiation. When particles escape, the black hole loses a small amount of its energy and therefore of its mass (mass and energy are related by Einstein's equation E = mc²). So the energy is eventually released in Gamma Radiation (high energy photons). Yes, the reason a black hole is created is because a high-massive star collapses on itself because it cant hold up against gravity. The star collapses into a single point with infinite mass. Since mass attracts more mass, its gravity pulls in more and more. The thing is, when you say "If over millions or billions of years" you are forgetting how gravity affects time. To put it simply... More Gravity=Slower Time Less Gravity=Faster Time So, as you know inside the singularity there is infinite density (mass divided by volume), this creates infinite gravity. Infinite gravity = Time Does Not Exist ! Therefore in fact, black holes have existed forever and will always continue to exist. But since we are not inside the blackholes singularity, time occurs differently, which is why we see it's death...Evaporation. I do apologize if I did a huge mind-phunk. Blackholes are a complicated subject. I hope I shed some light on it though, oh wait, light doesnt exist in a blackhole either.... ;)

Question: Where does the energy for gravity come from? According to the law of conservation of energy, energy is not created from nothing. It is either converted from mass or from other types of energy. In this case, where does the energy for gravity come from? For instance, the force pushing down the water in Niagara Falls is gravity, and we generate electricity from this energy. Where does this energy come from?

Answer: Gravity has no energy. the energy of Niagra falls comes from the rain. The sun's energy put the water higher than the falls. when the water is high, it is called potential energy. as the water is pulled lower, it releases energy; this is called kinetic energy. it is not the gravity that has the energy, it is the change in position of the water.

Question: What is energy and how does it influence matter? I know it is possible that sub-atomic particles are made of energy-like things called quarks. According to my understanding of them they are more like energy than they are like matter. Unfortunately I have a very basic understanding of these particles and their relationship with energy. I have books about sub-atomic particles but they don't really talk about the influence energy has on matter. Anyone wanna give me a crash course on energy? How would you define it and its effect? Thanks in advance.

Answer: Actually quarks are matter (mass is a better term); they are the fundamental building blocks of protons and neutrons. But from the well-known E = mc^2, where m is mass and c is light speed in a vacuum, we can easily see that all mass is equivalent to energy E. That is to say, we don't need to differentiate between mass and energy because they are just different states of the same thing. In fact, we often, and more correctly, say "mass-energy" when talking about matter because they are equivalent. On the other hand, we know that some particles do not behave like mass should behave. Photons are examples of such particles. For one thing, photons can travel at light speed; mass cannot. Mass cannot travel at light speed because, at that velocity, all mass has infinite inertia...which is why we frrequently call mass "inertial mass." For example, if we accelerate a proton to 99.99% of light speed, its inertial mass M will be 70.7 times m the rest mass of the proton when it is not moving. This does not mean the proton's mass grows in size, but it does mean it will be 70.7 times harder to move and/or change direction than when it was at rest. The power from nuke power plants and bombs comes from converting the mass states into energy states. What happens when we split or fuse mass particles (like plutonium or hydrogen) is that some of the mass loses its inertia and changes into energy. As a result, the sum of mass before the fission or fusion reaction is always greater than the sum of mass after it. And that mass difference is manifest as energy like heat, nuke radiation, light, and so on. E = mc^2 is a two-way street. We can and have created mass from energy in the lab. We can only do it in the lab because it takes an enormous amount of energy to make even the tiniest bit of mass. An interesting aspect of the energy to mass conversion is that we cannot make mass without also making anti-mass (i.e., anti-matter). For example, we cannot create an electron without creating the positron...the anti-electron. But the anti-matter is short lived and soon disappears as something else, like photons and/or some normal mass.

Question: What happens to the kinetic energy when the ball lands in a sand trap? (Select all that apply.) The sand is deformed, i.e. its potential energy has been increased. The speed of the ball, and hence its kinetic energy, drops to zero. The speed of the ball increases as it converts kinetic into potential energy. The kinetic energy is consumed by the ball. Most of the kinetic energy is transferred to the sand. The kinetic energy is transferred to the air. Some energy is released as heat through friction. The ball expands due to a heat increase.

Answer: The sand is deformed, i.e. its potential energy has been increased. true The speed of the ball, and hence its kinetic energy, drops to zero. usually true The speed of the ball increases as it converts kinetic into potential energy. false The kinetic energy is consumed by the ball. false, energy is not consumed. Most of the kinetic energy is transferred to the sand. true The kinetic energy is transferred to the air. some of it is Some energy is released as heat through friction. true The ball expands due to a heat increase. possibly true to a very small extent .

Question: What is the difference between thermal and internal energy? According to many sources, internal energy is the kinetic and potential energies of molecules of a substance - combined. Some sources also say that thermal energy is that definition. However, I don't think that thermal energy is kinetic and potential energy combined. I know that heat transfer occurs between a region with higher temperature and a region with lower temperature, but it isn't necessarily the case with two regions of different internal energies. So that seems to imply to me that temperature is a measurement of thermal energy - so in that sense thermal energy is merely the average kinetic energy of molecules and as such, doesn't include the potential energy. Is that right? Thanks (:

Answer: Yes, that is correct. Temperature is a measure of molecular kinetic energy. If you think of the conditions at absolute zero, 0 K (or -273 C) all molecular vibration stops, i.e. all kinetic energy goes to zero. Potential energy is energy stored in the molecular structure that can be released under a given condition. Example, explosive compounds have high potential energy. Under safe handling, room temperature conditions, the thermal kinetic energy will be the same as the lab table top. The combined internal energy is the kinetic plus potential energy.