PhySci Chpt 3-4
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T or F: The energy an object has because of its position is called potential energy.
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True.
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T or F: The increase in potential energy caused by lifting an object can be calculated by multiplying its weight by its change in height.
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True.
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T or F: Your electric bill for 1500 kilowatt-hours is a charge for the power you have used that month.
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False
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T or F: Plants convert radiant energy from the Sun into chemical energy by a process called photosynthesis.
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True.
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T or F: Nearly all of the energy consumed today is provided by petroleum, coal, hydropower and nuclear sources.
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True.
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The watt (W) is a unit of...
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Power.
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Which one of the following has an appropriate unit? work - joule force - newton power - watt All of the above.
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All of the above.
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Kinetic energy refers to...
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energy in motion.
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Which solar technology makes economic sense for a homeowner?
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water heating.
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What form of energy does not require matter for traveling through space?
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radient.
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Roughly, what fraction of our nation's current energy needs is supplied by coal?
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20%
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Energy sources used today are mostly in what form of energy?
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Chemical.
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T or F: Molecules are the smallest units of matter that retain the characteristic properties of a substance.
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True.
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T or F: Water beads up on wax paper because its cohesive forces are greater than the adhesive forces.
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True.
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T or F: Temperature is a measure of the amount of heat stored in a substance.
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False.
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T or F: The molecules of a gas are much farther apart than molecules in a solid or liquid.
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True.
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T or F: A liquid at 20ºC is twice as hot as the liquid at 10ºC.
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False.
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T or F: The degrees on the Celsius scale are larger than degrees on the Fahrenheit scale.
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True.
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T or F: The nutritionist's Calorie is really a kilocalorie.
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True.
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What is the average temperature of healthy humans on the Celsius scale?
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37º
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Molecules in a solid...
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are held in nearly fixed positions by strong attractive forces.
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When water vapor condenses to a liquid...
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it transfers heat to the surroundings.
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Your body judges temperature...
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very poorly, sensing only heat flow.
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The heat needed to warm one gram of water one Celsius degree is called a...
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calorie.
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Water molecules move back and forth between the liquid and gaseous phases...
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at all times.
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The transfer of heat that occurs when energy moves from molecules to molecule is called...
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conduction.
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Adding heat to a substance...
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sometimes does not result in a temperature change.
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The heat death of the universe is a theoretical time in the future when the universe is supposed to...
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freeze at a uniform low temperature.
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Which thermodynamic law says that you cannot convert 100 percent of a heat source into mechanical energy?
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second law of thermodynamics
