Energy


Question #1: According to the scientific definition of work, pushing on a rock accomplishes no work unless there is
(A). an applied force greater than its weight.
(B). a net force greater than zero.
(C). an opposing force.
(D). movement in same direction as the force.

#1 Answer
Question #2: The metric unit of a joule (J) is a unit of
(A). potential energy
(B). work
(C). kinetic energy
(D). all of the above

#2 Answer
Question #3: Power is
(A). the rate at which energy is expended.
(B). work per unit of time.
(C). the rate at which work is done.
(D). any of the above.

#3 Answer
Question #4: A Nm/s is a unit of
(A). energy.
(B). power.
(C). force.
(D). work.

#4 Answer
Question #5: The kilowatt-hour is a unit of
(A). power.
(B). work.
(C). time.
(D). force.

#5 Answer
Question #6: The potential energy of box on a shelf, relative to the floor, is a measure of
(A). the work done putting the box on the shelf from the floor.
(B). the weight of the box times the distance above the floor.
(C). the energy the box has because of its position above the floor.
(D). any of these.

#6 Answer
Question #7: Which quantity has the greatest influence on the amount of kinetic energy that a large truck has while moving down the highway?
(A). mass.
(B). weight.
(C). velocity.
(D). size.

#7 Answer
Question #8: Most all energy comes to and leaves the earth in the form of
(A). nuclear energy.
(B). chemical energy
(C). radiant energy.
(D). kinetic energy.

#8 Answer
Question #9: How many U.S. gallons of petroleum does the accounting device of a "barrel of oil" hold?
(A). 24
(B). 42
(C). 55
(D). 100

#9 Answer
Question #10: The law of conservation of energy is a statement that
(A). energy must be conserved and you a breaking a law if you waste energy..
(B). the supply of energy is limited so we must conserve.
(C). the total amount of energy is constant.
(D). energy cannot be used faster than it is created.

#10 Answer
Question #11: Energy is
(A). the ability to do work.
(B). the worked needed to create potential or kinetic energy.
(C). the work that can be done by an object with potential or kinetic energy.
(D). all of the above.

#11 Answer
Question #12: When you do work on something, you
(A). leave it with less energy than it had before.
(B). move it in a direction 90o to the direction of the applied force.
(C). give it energy.
(D). none of these.

#12 Answer
Question #13: An automobile engine with more power
(A). can do the same work at a lesser rate.
(B). can do less work over a greater time period.
(C). requires less time to do the same amount of work.
(D). none of these.

#13 Answer
Question #14: A light bulb rated at 100 W does not mention a time factor because the time is
(A). not used in power ratings of light bulbs.
(B). already included in the definition of a watt.
(C). considered in energy consideration other than light bulbs.
(D). not important because bulbs always use the same amount of energy.

#14 Answer
Question #15: Energy is conserved
(A). in any and all energy transformations.
(B). only when energy changes from one form to another.
(C). very rarely, since some is needed to run machines.
(D). most of the time, but not always.

#15 Answer
Question #16: How much work is done in raising a 10.0 kg backpack from the floor to a shelf 1.50 m above the floor?
(A). 150 J
(B). 155 J
(C). 15.0 J
(D). 15.1 J

#16 Answer
Question #17: If 5,000 J of work is used to raise a 100 kg crate to a high shelf in a warehouse, how high was the crate raised?
(A). 5 m
(B). 50 m
(C). 980 m
(D). 4020 m

#17 Answer
Question #18: A 60.0 kg student runs up a 5.00 meter high stairway in a time of 3.94 seconds. How many watts of power did she develop?
(A). 76.1 W
(B). 15.2 W
(C). 300 W
(D). 750 W

#18 Answer
Question #19: How many horsepower is a 1400 W blowdryer?
(A). 1.9 hp
(B). 2.5 hp
(C). 2.0 hp
(D). The answer to this question is not possible.

#19 Answer
Question #20: What is the kinetic energy of a 2,000 kg car that is moving at 72 km/h?
(A). 5184 kJ
(B). 400 kJ
(C). 20 kJ
(D). 40 kJ

#20 Answer
Question #21: How much work is needed to stop a 1,000.0 kg car that is moving straight down the highway at 54.0 km/h?
(A). 7.5 kJ
(B). 113 kJ
(C). 225 kJ
(D). 1,458 kJ

#21 Answer
Question #22: If you could "bundle" water, what would be the velocity of a water bundle that falls 100.0 m through the penstock of a hydroelectric dam?
(A). 44 m/s
(B). 1960 m/s
(C). 200.0 m/s
(D). 980 m/s

#22 Answer
Question #23: A 1000.0 kg car stops on top of a 50.0 m hill. How much energy was used in climbing the hill?
(A). 50,000 J
(B). 9,800 J
(C). 20 J
(D). 490 kJ

#23 Answer
Question #24: A 880 N box is pushed across a level floor for a distance of 5.0 m with a force of 440 N. How much work was done on the box?
(A). 2200 J
(B). 4400 J
(C). 6600 J
(D). 5500 J

#24 Answer
Question #25: A force of 200 N is needed to push a table across a level classroom floor for a distance of 3 m. How much work was done on the table?
(A). 600 J
(B). 200 J
(C). 203 J
(D). 5880 J

#25 Answer

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