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65 Cards in this Set
- Front
- Back
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the energy of an object that is stretched or compressed |
elastic potential energy |
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the energy of an object that is in motion |
kinetic energy |
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the ability to do work |
energy |
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the total energy related to the motion of all microscopic particles in an object |
thermal energy |
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the energy stored in chemical bonds |
chemical energy |
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the energy associated with the motion and position of objects |
mechanical energy |
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the energy that travels through space in the form of waves |
electromagnetic energy |
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the energy stored in atomic nuclei |
nuclear energy |
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the energy associated with electric charges |
electrical energy |
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the energy that depends upon an object's height |
gravitational potential energy |
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the energy that is stored as a result of position or shape |
potential energy |
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the transfer of energy by waves moving through space |
radiation |
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circulation of a fluid in a loop as it alternates between hot and cold |
convection current |
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thermal energy that is not converted into work |
waste heat |
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material that conducts thermal energy poorly |
thermal insulator |
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the transfer of thermal energy as particles of a fluid move from place to place |
convection |
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the study of conversions between thermal energy and other forms of energy |
thermodynamics |
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a device that converts heat into work |
heat engine |
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the transfer of thermal energy between materials that are touching |
conduction |
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material that conducts thermal energy well |
thermal conductor |
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True or False The everyday meaning and the scientific meaning of "work" can be quite different. |
True |
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True or False Actual and ideal mechanical advantage can be the same because the force of friction can be eliminated with lubricants and low friction materials. |
False |
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True or False Screws with fewer threads per inch have a smaller ideal mechanical advantage than screws with more threads per inch |
True |
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True or False The ideal mechanical advantage of a pulley system is equal to the number of rope sections supporting the load being lifted. |
True |
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True or False Energy cannot be created, destroyed, or converted form one form to another. |
False |
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True or False The effects of friction cannot be ignored under any circumstances. |
False |
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True or False
Energy is released as matter is destroyed; however, matter cannot be created from energy |
? Check book and study guide |
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True or False Energy has always been as important to humankind as it is now. |
? Check book and study guide |
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True or False Air pollution, acid rain, and global warming are the only environmental problems associated with fossil fuels |
False |
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True or False Because natural gas is odorless, a strong odor is added to aid in detecting leaks. |
True |
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True or False Uranium has no environmental problems associated with it since it is not burned like fossil fuels are. |
False |
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True or False No heating or cooling system is 100% efficient |
True |
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True or False, if false replace the bold word with a word that makes the statement true. A heat ENGINE reverses the normal flow of thermal energy |
false, heat pump |
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True or False, if false replace the bold word with a word that makes the statement true. Most central heating systems use CONDUCTION to distribute thermal energy. |
false convection |
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True or False, if false replace the bold word with a word that makes the statement true. Only about ONE-THIRD of the energy of gasoline is converted to work for a car. |
true ?check answer in book |
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True or False, if false replace the bold word with a word that makes the statement Most cars have an EXTERNAL combustion engine that burns gasoline |
false, internal |
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True or False, if false replace the bold word with a word that makes the statement true. The FAHRENHEIT temperature scale is typically used only for weather and other day-to-day activities. |
True |
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True or False, if false replace the bold word with a word that makes the statement true. Scissors are a compound machine consisting of two levers and two INCLINED PLANES |
True |
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True or False, if false replace the bold word with a word that makes the statement true. The mechanical advantage of a machine is the number of times the OUTPUT force is multiplied by the machine |
false, input |
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True or False, if false replace the bold word with a word that makes the statement true. The work done by a machine is GREATER than the work done on the machine |
False, less |
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True or False, if false replace the bold word with a word that makes the statement true. Doing work at a faster rate requires more POWER |
true |
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The ideal mechanical advantage of an inclined plane that has a length of 4.5m and a change of height of 0.3 m is |
MA = di/do = 4.5/0.3 = 15 |
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Machines can make doing jobs easier by a) changing the size of the force needed. b) changing the direction of the force needed c) changing the distance over which a force acts d) all of the above e) A and B only |
d) all of the above |
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Which of the following statements is true? a) geothermal power is unreliable b) wind power is the fastest growing types of electrical power c) twenty-seven percent of US electrical generation is hydroelectric d) solar power cells are used for large appliances |
I think b but Check study guide and book |
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Which stroke of a four-cycle internal combustion engine does the work? |
power stroke |
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A tractor pulls a wagon at a constant velocity for 1500 m while exerting a force of 600 N Calculate the work. |
W = F * d = 600 *1500 = 600,000 J |
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A tractor pulls a wagon at a constant velocity for 1500 m while exerting a force of 600 N. If the pull takes 120 seconds, how much power (in watts) is necessary? |
P = W/t = 600,000/120 = 5000 W |
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A tractor pulls a wagon at a constant velocity for 1500 m while exerting a force of 600 N Calculate the approximate power in horsepower (1 horsepower = 746 W) |
5000/746 = 7 horsepower |
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When you exert 75 N on a jack to lift a 6000 N car, what is the jack's actual mechanical advantage? |
MA = Fo/Fi = 6000/75 = 80 |
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Calculate the efficiency of a machine that has a work output of 20 J and a work input of 27 J. Show your work and round your final answer to the nearest tenth. |
Eff = Wo/Wi X 100 = 20/27 X 100 = 74.1% |
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List six types of simple machines. |
1. lever 2. incline plane 3. wedge 4. screw 3. wheel and axle 4. pulley |
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Calculate the ideal mechanical advantage of a screwdriver that is used to open a paint can. The input arm is 18 cm and the output arm is 0.75cm |
MA = di/do = 18/0.75 = 24 |
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A bicycle and its rider have a combined mass of 125 kg and are traveling at a velocity of 4 m/s. What is their kinetic energy? |
KE = 1/2*m*v*v = 1/2(125)(4)(4) = 1000 |
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At what point does a pendulum on a clock have maximum potential energy? |
when at its highest point of swing |
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At what point does a pendulum on a clock have maximum kinetic energy |
at the bottom of swing because it has the fastest speed. |
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List four nonrenewable energy sources |
coal oil natural gas uranium |
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List four currently available renewable energy sources. |
wind solar hydroelectric geothermal |
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Explain how the Celsius scale was formulated |
freezing point of water was set at 0 and boiling point at 100 to form the scale |
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What does absolute zero in kelvins represent? |
The point at which all motion of particles stops |
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What is meat by the term specific heat? |
The amount of heat needed to raise one gram of substance one degree Celsius. |
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Using the formula Q=mcT calculate how many joules of heat are added to 1500 g of water to raise the temperature from 15 degrees to 80 degrees celcius (The specific heat of water = 4.18) |
Q = 1500(4.18)(80-15) = 407,550 J |
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Would Q=mcT work if the final temperature were 110 degrees celcius? why or why not? |
No because some of the heat would be used to change the water molecules from a liquid to a gas |
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The first law of thermodynamics states that energy is conserved. As a practical matter, what does this mean? |
energy is not created or destroyed it is just transferred from one object to another |
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The second law of thermodynamics states that the heat flows from warmer to cooler objects. Can the reverse ever happen? |
No the warmer molecules transfer energy to the slower moving cooler molecules a colder molecule would not be able to pass energy to a warmer one. |
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What does the third law of thermodynamics state? |
As temperature on a Kelvin scale reaches zero motion of particles slows to a minimum (almost a stop) |
