Physics Exam review
Terms
copy deck
 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?
 100N
 A force is exerted on the tires of a car to accelerate the car along the road. The force is exerted by:
 friction
 If Kelly the skater's speed increases so he has twice the momentum, then his kinetic energy increases by:
 4 times
 Acceleration is defined as the CHANGE in:
 velocity/time
 Suppose a moving car has 2000J of kinetic energy. If the car's speed doubles, how much kinetic enrgy would it then have?:
 800J
 The earth pulls on the moon, and similarly the moon pulls on the earth. This is evidence of:
 Newtons 3rd law
 A 10N object moves at 1m/s. Its kinetic energy is:
 5J
 Physics is the most basic science because:
 it's about the world around us.
 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:
 2 meters
 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:
 glove against ball
 A pulley system can:
 change direction and multiply force
 Speed is:
 distance/time
 About how effcient is a typical gasolineburning car engine?
 30%
 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:
 ALWAYS TRUE
 The ratio of output force to input force of a simple machine is called:
 efficiency
 When you look at the speedometer in a moving car, you can see the car's:
 instaneous speedthe speed at any given second.
 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:
 limousine
 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:
 Same
 How much power is required to do 100J of work on an onject in 2 seconds?:
 50W
 Teh difference between a Theory and a Hypothesis is:
 A Theory is a guess, you have tested it, and it can't be proven wrong. A Hypothesis is an educated guess, not tested.
 How many joules of work are done on an object when a force fo 10N pushes it 5m?
 50J
 A karate chop delivers a blow of 3000N to a board that breaks. The force that acts on the hand during this feat is:
 3000N
 Consider molecules of hydrogen gas and molecules of heavier oxygen gas that have the same kinetic energy. The molecules with more speed are:
 hydrogen gas
 One possible unit of speed is
 meters/second;kilometers/hr.
 All simple machines ideally work on the principle that:
 work input=work output
 An unfortuanate bug splatters against the windshield of a moving car. Compared to the deceleration of the car, teh deceleration of the bug is:
 much greater
 The ratio of useful work output to total work input is called the:
 efficiency
 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:
 True
 How much work is done on a 50N rock that you carry horizontally across a 10m room?
 0
 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?:
 Yes
 How much work is done on a 50N rock that you lift 10m?:
 500J
 Forces always occur in:
 Pairs
 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.
 energy
 An archer shoots an arrow. Consider the action force to be the bow string against the arrow. The reaction force is:
 arrow against the bowstring
 How much power is expended if you lift a 50N rock 10 meters in 1 second?:
 500W
 How much farther will a car traveling at 100km/s skid thatn the same car traveling at 50km/s?:
 four times as far
 Ten seconds after starting from rest, a car is moving at 40m/s. What is the car's average accerleration.
 4m/s squared
 The unit of work is the:
 joule
 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:
 0/it is staying the same
 If you lift one load up two stories, how much work do you do compared to lifting one load up only one story?:
 twice as much
 A job is done slowly and identical job is done quickly. Both jobs require the same amount of work but different amounts of :
 power
 Potential energy is the energy an object has because of its:
 location or position
 Which has greater kinetic energy, a car traveling at 30km/h or a halfasmassive car traveling at 60km/h?:
 car moving at 60km/h
 Kinetic energy of an object is equal to:

1 2
 mass x velocity
2
(1/2 mass x velocity squared)  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:
 acceleration
 The unit of power it the:
 Watt
 An object that has linear kinetic enrgy must be _______:
 moving
 If Nellie Newton pushes an object with twice the force for twice the distance, she does________:
 four times the work
 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:
 same100J
 Power is defined as the:
 work/time
 Energy is changed from one form to another with no net loss or gain: True or False:
 ALWAYS TRUE
 The amount of potential energy possessed by an elevated object is ewual to:
 mass x gravity x height
 An object that has kinetic energy MUST BE:
 moving
 If you lift two loads up one story, how much work do you do compared ot lifting just one load up one story?:
 twice as much
 An object that has kinetic energy must HAVE:
 momentum
 Work is defined as:
 force x distance
 Which requires more work: lifting a 50kg sack vertically 2 meters or lifting a 25kg sack vertically 4 meters?:
 same
 Bullets are fired from an airplane in the forward direction of motion. the momentum of the airplane will be______:
 decreased
 If an object has kinetic energy, then it also MUST HAVE:
 momentum
 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?:
 100Jsame
 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?:
 70J
 An object at rest May have:
 potential energy
 As a pendulum swings back and forth:
 it changes from potential to kinetic
 If the velocity of a moving object doubles, then what else doubles?:
 momentum doubles