Conceptual Physics Test 1 Questions and Answers All Correct

Conceptual Physics Test 1 Questions and Answers All Correct What is energy? - Answer-the ability to do work What happens to energy in an explosion? - Answer-stored energy is released and converted into heat in a small space, heat vaporizes matter turning into hot gas. What happens when the conversion of heat in an explosion is faster? - AnswerExplosion becomes more dangerous. (a fast conversion of energy to heat causes an explosion) Any form of energy can be converted into what? - Answer-Heat What can energy be measured in? (Units of energy) - Answer-Calories (C), Calories (c), Kilowatt-hours, or Joules What is a calorie (C) - Answer-Used to measure food energy How many joules are in a Calorie? - Answer-4200 joules How many joules are in a kilowatt-hour (kWh)? - Answer-3.6 million joules What is a Kilowatt-hour (kWh)? - Answer-Electric energy 1 kilowatt hour equals how many watt-hours? - Answer-1000 watt-hours 1 kilowatt hour equals how many Calories? - Answer-1000 Calories Do different materials of the same amount have the same amount of energy? - AnswerNo, the same amount of different material have a different amount of energy. Why is 1 gram of a cookie have 8 times greater energy than 1 gram of TNT - AnswerTNT releases energy extremely fast making it more dangerous. A cookie release energy slower give it more energy than the TNT Why is gasoline popular to use as fuel - Answer-Gasoline contains more energy per gram than coal or ethanol and leaves no residue except gas How does gasoline release its energy - Answer-by combining the heat released with oxygen What does batteries store - Answer-chemical energy What is chemical energy capable of - Answer-releasing electrons of their atoms which carries its energy electric energy is easily - Answer-transportable Why are batteries used to start a car rather than gasoline - Answer-batteries contain a low amount of energy, batteries are used to start because they are fast and gasoline is used as its source In an automobile battery lead and sulfuric acid react to generate - Answer-electricity why are hybrid engines more energy efficient than the regular car engines. - AnswerHybrid engines can convert some of the mechanical energy of the car back to stored chemical energy in the rechargeable battery What is the cheapest source of energy? - Answer-coal why don't we use coal in our cars, to heat our homes, and for cooking - AnswerBecause gasoline contain more energy per gram than coal and is one of the worst carbon dioxide polluters What motion uses more kinetic energy - Answer-The faster the motion, more kinetic energy is has What is potential energy - Answer-stored energy What has more gravitational energy - Answer-an object higher than another. The higher the elevation, the more gravitational energy an object contains What is an example of conversion of gravitational energy to kinetic energy - Answer-A book on a top shelf that has more gravitational energy falling converting its energy into kinetic due to its motion. Loosing 100 joules of gravitation energy due to decreasing height 100 joules of kinetic energy is gained due to its speed what is power - Answer-the rate of energy transfer. In other words, how fast the energy is transferred. Power = Energy / time what is power measured in - Answer-watt, W (one Joule per second) or in horsepower, hp ( 0.18 Calorie per second) Power efficacy - Answer-(useful energy/total input energy) x 100. There's always energy loss. Therefore all power have less than 100% efficiency