Exam 1 Cheat Sheet PDF

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Exam 1 Cheat Sheet...

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CHAPTER 1 Explosion- Lots of stored energy converted to heat in a space. It doesn’t matter how much energy for an explosion, but how rapid the conversion of energy to heat is. Energy- Ability to do work. Energy: Calorie; kilowatt-hour; Joules. Power: kilowatt; J/S. Chocolate chip cookies have 8 times energy as TNT, but metabolism is slower (less power). Gasoline is popular because of its high energy per gram. Hydrogen must be created rather than mined through electrolysis of water. Its density is .071 grams per cc, 10 times less than gas. Stores 0.18 times as much as gas. Hydrogen is also not a source of energy, but a means of transporting it. ;; U-235 has 30 million times energy of TNT. It is released through chain reaction. Coal is cheap. Power = Energy/Time. First Law of Thermodynamics: Any energy that appears to be lost just turns into heat. Conservation of energy is that the total energy is always the same. 2nd law: can’t convert heat energy to work. 3rd law: Refrigerators cannot reach absolute zero. Zeroth Law: Objects in contact tend to reach the same temperature. Calorie- The energy it takes to raise one kilogram of water by one degree Celsius. 4200 Joules = 1 Calorie. Nano, Micro, Milli, Kilowatt, Megawatt (10^6), Gigawatt (10^9). Incandescent vs Fluorescent light bulb. Brightness of bulb depends on power. For Solar Power: 1 square meter  1 kilowatt of sunlight, 150-400 watts electric using solar cells, 1 square kilometer  1 gigawatt of sunlight, 150-400 megawatts electric Horsepower is 1 kilowatt. Kinetic energy = ½ mv^2. CHAPTER 2 Heat is kinetic energy. When molecules break apart or come together it’s called a chemical reaction. Speed of light: 186,000 miles per second. Asteroid hit earth 65 million years ago. Temperature is a measure of the hidden kinetic energy of the molecules. Zeroth Law of Thermodynamics: Objects in contact tend to reach the same temperature. Tc = (Tf – 32)(5/9). Tf = (9/5)Tc + 32.Tc = Tk Freezing Water: Tf=32,Tc=0. Boiling: Tf=212,Tc=0. Room Temperature: Tc=20,Tf=68. When the atoms in a solid heat up they move faster and tend to push their neighbor atoms farther away. Cold water expands when it is further cooled. Once water gets colder than 4C, the freezing water expands with its low density it floats on top of the other water. Gases usually take 1000 times the volume of a solid, and 100 times liquid. Ideal Gas Law: Pressure of gas = constant * Tk. Constant is just a factor number. For typical automobiles, only about 10% to 30% is actually useful. Efficiency ≤ 1- (Tcold/Thot). Conduction: Energy flows by contact. A good conductor is something that transfers heat rapidly from one molecule to the next. Convection: Energy is carried by a moving material (usually gas or liquid). Radiation: Energy moves through empty space carried by light (radiation is used for any energy flowing through space). Total change in entropy = Q/Tc – Q/Th. Entropy of universe tends to increase, and entropy of object goes to zero at T = 0K CHAPTER 3 Weight is the gravitational force on the planet. 1 kg = 2.2 lbs. Newton’s law of gravity Law of inverse square law:F = G

Mm r2

. Mass of the object being pulled, and r is the distance between them. G is G=6.67 x 10^-11. Surface of the

Earth: r = 4000 mile. 1/r^2 = 1/16,000,000. Satellite: r = 4100 miles. 1/r^2 = 1/16,810,000. Weightlessness (astronauts fall freely so appear that way). Newton’s First Law: An object in motion tends to stay in motion unless there is an outside force. Newton’s Second Law: F = ma. Newton’s Third Law: If an object exerts a force on you, then you exert the same force back on it. Satellites are shot on an arc, they rotate around earth the faster the velocity. Low Earth Orbit takes 90 minutes to go around Earth (24,000 mile circumference), and just a few hundred miles above the surface. Geosynchronous Satellites: Orbited at 22,000 miles altitude. Takes 24 hours to orbit Earth. Spy Satellite: Close to earth, LEO orbit, 16,000 mph. They cannot hover, because if they lose velocity they fall to earth. GPS- MEO Satellite (orbits Earth every 12 hours). Orbital velocity: 5 m/s, Escape velocity: 7 m/s. Usually science fiction movies assume that all planets have Earth’s gravity. F = ma. Cars must make up for their lost energy from the force of air on its front through exerting an equal and opposite force. Larger air resistance causes satellite to crash if its too low to ground. Circular acceleration: a = v^2/r. Centrifuge is a high g used to separate the components of uranium for making a nucklear weapon. Black holes have an escape velocity higher than the speed of light. Conservation of Momentum: MbVb = MaVa. Project Skyhook is building a tower up to space (requires 15 Cal/g). Airplanes fly by pushing air downward. Air is less dense than plane. Density of hot air is less than cold air- hot air expands. Less dense things float (Below 1 g/cm^3).Pressure decreases as you go up to the sky. Storm surge is when water in center of hurricane rises. The winds of a hurricane are a result of rapidly rising hot air. Angular momentum: L = MvR. In class sitting on chair and bringing arms back; L and M are the same for that, but vR is not. R is less and v has to in turn be more. CHAPTER 4 Radioactivity: Explosion of the nucleus of the atom. Nucleus is 10^-13 cm. Protons weigh 2000 times as much as electrons. Neutrons have similar mass as protons. Atom is very small nucleus made of protons and neutrons. Protons and neutrons made of quarks and gluons. Matter made of molecules. Molecules made of atoms. Nuclei made of protons, neutrons, other light particles. Quarks and electrons made of strings. Periodic table shows 92 different atoms. Atomic number shows how many protons are in an atom. Atom diameter is 10^-8 cm. Alpha rays, beta rays, gamma rays (in order of strength  more strength). When alpha or beta rays pass through a gas, they knock electrons off atoms creating ions. Cloud chamber has short white lines of cloud particles forming along a path. Cosmic radiation is a long path to the cloud chamber. The biological damage done to cells hit by radiation is measured in rem. 2 billion gamma rays covering each square centimeter of your body results in 1 rem. 100 rem = 1 Sievert. Below 100 rem, no illness. 100 to 200 rem, slight illness. 300 rem, 50% chance death if untreated w/in 60 days. More than 1000 rem, incapacitation soon. 300 rem is LD50. Alexander Litvinenko (Federal Security Service) died three weeks after he fled to London. He suffered over 1000 rem, 0.05 curies of radioactive isotope polonium-210. A photographer’s antistatic brush contains 250 microcuries of Po-210, and in order to have an equivalent amount that Litvinenko died from, then Id have to order 200 of them. It is actually very difficult to assassinate someone like that, so someone must have wanted to assassinate him in a dramatic way. The average dose that it takes to induce cancer is whole-body does of 2500 rem. If someone gets 25 rem, it amounts to 1% of a 2500 rem cancer dose. 20% of the population dies from natural cancer. With a small dose, there is always a proportionate chance cancer will be induced called linear effect. Chernobyl disaster: 1986. Chernobyl power plant in Ukraine had accident. Explosion is vessel which had radioactive fuel, radioactivity was released into atmosphere. Wind carried the radioactivity to other areas. 25,000 to 40,000 peopld had median dose of 45 rem. The total dose to the world population was 60,000,000 rem. Total dose = ((Total Population)(Average dose)(years)) / 2500. Fewer than 2% of deaths caused by atomic bomb was cancer in Hiroshima. 52,000 survivors received 0.5 rem or more, and average dose for people was 20 rem. Estimates of deaths were between 50,000 and 150,000. Cancer deaths could have been higher if the bomb exploded closer to the ground rather than at high altitude because that increases amount of radioactive fallout. Denver emits higher than average amounts of radioactive gas radon. 0.1 rem per person per year. For 2.4 million people in Denver for 50 years, F(0.1)(2.4*10^6)(50)=1.2*10^7. Nobody knows why Denver has a low amount of overall cancers though. Typical dental x-ray is 1 millirem. Treating cancer through radiation to destroy cancer cells. Radiation treatment is combined with chemotherapy. Dirty bomb releases a lot of radioactivity. Alpha rays (2 protons, 2 neutrons) at high velocity, beta rays (energetic electrons), gamma rays (energetic light), x-rays (like gamma rays but less energetic). Fission is when a nucleus splits into two or more pieces. Neutrinos are strongly emitted by the sun.. On average, half of the carbon-14 atoms in your body will explode in 5730 years, called the half-life. Radioactive decay is the reduction of radiation. Radiocarbon dating uses Carbon-14 to measure age of fossils. Alcohol cannot be created from petroleum in US, and petroleum formed from living matter that died over 50,000 C-14 half lives ago. No detectable C-14 in it. US checks if alcohol has C-14, and if so, then people can drink it, else not. After 10 half-lives, the radioactivity decreases by a factor of (1/2)^10. You can get more radioactive when you breathe it in or if it gets stuck on you. Neutrons cause radioactivity (like C-12 to C-14 by adding two neutrons). Neutron activation is making an atom radioactive by hitting it with neutrons. Plutonium is dangerous but alpha ray. Fission is spontaneous or induced. Spontaneous is random time it splits. Induced fission is when neutron is absorbed and the nucleus becomes unstable and fissions. Fusion is source of energy for the sun. Earth is 4.5 billion years old.

CHAPTER 5 When a neutron hits a uranium-235 nucleus, it has a high probability of fission. Microwaves are not ionizing radiation. Ionizing radiation is energy in the form of waves/particles which has sufficient energy to ionized matter. Critical mass is minimum amount to start chain reaction. Depleted uranium is when U-235 is enriched and there is some U-238 left over. Three Mile Island- Control rods plunged into reactor core in 1979....