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64 Cards in this Set
- Front
- Back
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A frictionless inclined plane is 6m long and rests on a wall that is 2m high.How much force is needed to push a block of ice weighing 300N up the plane?
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100N
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A force is exerted on the tires of a car to accelerate the car along the road. The force is exerted by:
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friction
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If Kelly the skater's speed increases so he has twice the momentum, then his kinetic energy increases by:
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4 times
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Acceleration is defined as the CHANGE in:
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velocity/time
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Suppose a moving car has 2000J of kinetic energy. If the car's speed doubles, how much kinetic enrgy would it then have?:
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800J
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The earth pulls on the moon, and similarly the moon pulls on the earth. This is evidence of:
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Newtons 3rd law
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A 10-N object moves at 1m/s. Its kinetic energy is:
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5J
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Physics is the most basic science because:
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it's about the world around us.
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A pulley has two supporting strands. In order to use it to lift a load 1 meter, the person pulling will have to pull a distance of:
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2 meters
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A player catches a ball. Consider the action force to be athe impact of the ball against the player's glove. What is the reaction force:
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glove against ball
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A pulley system can:
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change direction and multiply force
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Speed is:
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distance/time
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About how effcient is a typical gasoline-burning car engine?
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30%
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Whenever an object exerts a force on another object, hte second object exerts a force of the same magnitude, but in the opposite direction to that of the first object. TRUE or FALSE:
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ALWAYS TRUE
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The ratio of output force to input force of a simple machine is called:
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efficiency
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When you look at the speedometer in a moving car, you can see the car's:
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instaneous speed-the speed at any given second.
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A small economy car(low mass) and a limosuine(high mass) are pushed from rest across a parking lot, equal distances with equal forces. The car that receives more change in kinetic energy is the:
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limousine
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An unfortunate bug splatters against the windshield of a moving car. Compared to the force of the car on the bug, the force of the bug on the car is:
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Same
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How much power is required to do 100J of work on an onject in 2 seconds?:
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50W
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Teh difference between a Theory and a Hypothesis is:
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A Theory is a guess, you have tested it, and it can't be proven wrong. A Hypothesis is an educated guess, not tested.
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How many joules of work are done on an object when a force fo 10N pushes it 5m?
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50J
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A karate chop delivers a blow of 3000N to a board that breaks. The force that acts on the hand during this feat is:
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3000N
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Consider molecules of hydrogen gas and molecules of heavier oxygen gas that have the same kinetic energy. The molecules with more speed are:
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hydrogen gas
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One possible unit of speed is
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meters/second;kilometers/hr.
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All simple machines ideally work on the principle that:
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work input=work output
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An unfortuanate bug splatters against the windshield of a moving car. Compared to the deceleration of the car, teh deceleration of the bug is:
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much greater
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The ratio of useful work output to total work input is called the:
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efficiency
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Your friend says that the heavyweight champion of the world cannot exert a force of 50N on a piece of tissue paper with his best punch. The tissue paper is held in midair, no wall, noa tricks. TRUE or FALSE:
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True
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How much work is done on a 50N rock that you carry horizontally across a 10m room?
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0
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If a horse pulls on a wagon at rest, the wagon pulls back equally as much on the horse. Will the wagon be set in motion?:
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Yes
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How much work is done on a 50N rock that you lift 10m?:
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500J
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Forces always occur in:
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Pairs
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A popular swinging apparatus consists of an aligned row of identical elastic balls suspended by strings so they touch each other. When two balls on one end are elvated and released, they slam into the array of balls and two balls pop out the other side. If instead, one ball popped out with twice the speed, this would be a violation of the conservation of_____:
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energy
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An archer shoots an arrow. Consider the action force to be the bow string against the arrow. The reaction force is:
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arrow against the bowstring
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How much power is expended if you lift a 50-N rock 10 meters in 1 second?:
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500W
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How much farther will a car traveling at 100km/s skid thatn the same car traveling at 50km/s?:
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four times as far
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Ten seconds after starting from rest, a car is moving at 40m/s. What is the car's average accerleration.
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4m/s squared
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The unit of work is the:
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joule
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An object travles 2 meters in the first second of travel, 2 meters again during the second second of travel, and 2 meters again during the third second. It's acceleration is:
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0/it is staying the same
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If you lift one load up two stories, how much work do you do compared to lifting one load up only one story?:
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twice as much
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A job is done slowly and identical job is done quickly. Both jobs require the same amount of work but different amounts of :
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power
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Potential energy is the energy an object has because of its:
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location or position
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Which has greater kinetic energy, a car traveling at 30km/h or a half-as-massive car traveling at 60km/h?:
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car moving at 60km/h
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Kinetic energy of an object is equal to:
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1 2
- mass x velocity 2 (1/2 mass x velocity squared) |
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A heavy object and a light object are released from rest at the same height adn time in a vacuum. As they fall, they have equal:
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acceleration
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The unit of power it the:
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Watt
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An object that has linear kinetic enrgy must be _______:
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moving
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If Nellie Newton pushes an object with twice the force for twice the distance, she does________:
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four times the work
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A ball is thrown into the air with 100J of kinetic energy which is transformed to gravitational potential energy at the top of its tragectory. When it returns to its original level after encountering air resistance, its kinetic energy is:
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same-100J
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Power is defined as the:
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work/time
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Energy is changed from one form to another with no net loss or gain: True or False:
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ALWAYS TRUE
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The amount of potential energy possessed by an elevated object is ewual to:
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mass x gravity x height
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An object that has kinetic energy MUST BE:
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moving
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If you lift two loads up one story, how much work do you do compared ot lifting just one load up one story?:
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twice as much
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An object that has kinetic energy must HAVE:
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momentum
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Work is defined as:
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force x distance
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Which requires more work: lifting a 50-kg sack vertically 2 meters or lifting a 25-kg sack vertically 4 meters?:
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same
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Bullets are fired from an airplane in the forward direction of motion. the momentum of the airplane will be______:
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decreased
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If an object has kinetic energy, then it also MUST HAVE:
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momentum
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A person on a roof throws one ball downward and an identical ball upward at the same speed. The ball thrown downward hits the ground with 100J of kinetic energy. Ignoring air friction, with how much kinetic energy does the second ball hit the ground?:
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100J-same
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An arrow in a bow has 70J of potential energy. Assuming no loss of energy due to heat, how much kinetic energy will it have after it has been shot?:
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70J
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An object at rest May have:
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potential energy
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As a pendulum swings back and forth:
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it changes from potential to kinetic
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If the velocity of a moving object doubles, then what else doubles?:
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momentum doubles
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