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Energy Unit 4,5,9
Question | Answer |
---|---|
In Science, this is defined as “when a force moves an object a distance.” | Work |
The ability to do work or cause changes in matter | Energy |
The SI unit for Work and energy | Joule |
One of the two main types of energy: energy that is stored; the energy of position or height of an object above the earth's surface. | Potential Energy |
One of the two main types of energy: the energy of motion | Kinetic Energy |
When a book is dropped, it has this kind of energy. | Kinetic Energy |
A stretched rubber band is an example of this. | Elastic Potential Energy |
The fuel used by a rocket stores energy as this. (All food and fuels store this energy.) | Chemical Potential Energy |
An object held up above the surface of the ground has this. | Gravitational Potential Energy |
The higher an object is above the ground... | The more gravitational potential energy the object has. |
Once used, these can be easily replaced. | Renewable Resources |
Water, wind, and sunlight are examples of these. | Renewable Resources |
Once used, these cannot be easily replaced. Uranium is one example of these. | Nonrenewable Resources |
Petroleum, natural gas, and coal are all this: | Fossil Fuels (Nonrenewable Resources) |
How are fossil fuels produced? | Fossil Fuels are created from decayed materials by heat and pressure over many millions of years. |
A new fuel made from renewable organic material from plants or animals | Biomass Fuels |
Electricity produced by combining Hydrogen and Oxygen gases with water as the only byproduct | Hydrogen Fuel Cells |
Electricity produced when falling or running water turns a generator. | Hydropower or Hydroelectricity |
What is a disadvantage of using hydroelectric power? | Hydroelectricity can disturb natural ecosystems, because dams are often built to control it. |
Thermal energy from the ground (often in the form of magma) harnessed for electricity or heat. | Geothermal |
Electricity produced when wind turns a propeller which then turns a generator. | Wind power |
What are the advantages of using wind power? | Wind power is clean, inexpensive and available everywhere. |
What are the disadvantages of using wind power? | The wind must be blowing. Large wind farms produce noise, and may have ecological effects. |
Electricity generated by sunlight hitting a photovoltaic cell | Solar power |
The form of energy caused by motion of mechanical parts (like windmills and buses) | Mechanical Energy |
The form of energy due to the movement of electrically charged particles | Electrical Energy |
The form of energy related to the movement of atoms that make up matter (more is produced as the atoms move faster) | Heat Energy |
This form of energy is in the form of electromagnetic radiation released as photons by vibrations in electrons (light waves, x-rays, radio waves...) | Radiant Energy |
The form of energy that comes from the fusion or fission of the center of an atom (nucleus) | Nuclear Energy |
What is the fuel most often used for nuclear energy? | Uranium |
The form of energy created by movement of air molecules caused by vibration (loudspeakers produce this) | Sound Energy |
The form of energy stored in the bonds of molecules in food and fuels (like gasoline) | Chemical Energy |
The formula for kinetic energy | KE (J) = 1/2 m (kg) x v2 (m2/s2) |
The formula for gravitational potential energy | GPE (J) = m(kg) x 9.8 m/s2 x h (m) |
The formula for Work | Work = Force * distance => W (J) = F (N) * d (m) |
According to the law of conservation of energy, what is true about the total amount of energy in the universe? | The total amount of energy in the universe remains CONSTANT. |
What does the Law of Conservation of energy state? | Energy may change from one form to another, but the total amount of energy in the Universe never changes. |
Sulphuric acid mixes with water vapor to make this. | Acid rain |
What gas produced by burning fossil fuels is thought to lead to global warming? | Carbon dioxide |
What is the biggest problem with our continued use of fossil fuels? | Fossil fuels are a nonrenewable resource. |
The form of energy due to the attraction between two objects due to their masses and distance apart. | Gravitational energy |
The form of energy due to the attraction of objects made of iron, nickel, or cobalt. | Magnetic energy |
A measure of the average kinetic energy of the particles in an object | Temperature |
How is an object's thermal energy related to its temperature? | Because thermal energy is the sum of all the kinetic and potential energy of all the particles in an object, as its temperature (heat => KE) increases, its thermal energy increases. |
The transfer of thermal energy (heat) by collisions between the particles in matter (contact) | Conduction |
The transfer of thermal energy (heat) in a fluid (liquid or gas) by the movement of warmer and cooler parts of the fluid. | Convection |
What is the pattern of motion of the fluids in thermal transfer by Convection? | Hot fluids rise and spread out, while cool fluids sink, creating convection currents. |
The transfer of energy by electromagnetic waves (infrared) that can travel through empty space | Radiation |
What is an insulator? | A material in which heat flows slowly |
What are some materials that are good insulators? | Wood, plastics, fiberglass, air, Styrofoam, and fleece |
Almost all energy on earth comes from this source. | The Sun |
Solve the following: Two students rearrange a room by moving a desk 3.0 m across the room. If they exert a horixontal force of 200 N, how much work have they done? | 600 Nm or J |
Sierra serves a volleyball with a mass of 2 kg. The ball leaves her hand with a speed of 30 m/s. What is the kinetic energy of the ball? | 900 J |
The potential energy of an apple is 6 J. It is sitting on a shelf that is 3 m high. What is the mass of the apple? | .20kg |