# Shared Flashcard Set

## Details

Physics Pre-Comps
These are the flashcards for everything we did in Physics this year so far
149
Physics
12/22/2010

## Additional Physics Flashcards

Term
 What is the Scientific Method?
Definition
 1. Recognize a problem or something unknown 2. Make a hypothosis 3. Make predictions about your hypothosis 4. Perform expirements to test your hypothosis 5. form a conclusion 6. relay your data
Term
 What is a scientific hypothosis?
Definition
 an educated guess that must be tested by expirements
Term
 When is a hypothosis proven through expirements?
Definition
 Never
Term
 How many expirements can prove you wrong?
Definition
 One
Term
 What is science?
Definition
 The study of the universe
Term
 What si a Quantative measurement?
Definition
 a measurement that produces a definite, specific value:   Ex: Classes at BASIS are normally 50 minutes long
Term
 What is a Qualitative Measurment?
Definition
 a measurement that is a non-numerical (no numbers) discription    Ex: Classes at BASIS are just the right length
Term
 The Metric System. What are the common units?
Definition
 Length -meters Mass -grams  Weight -Newtons Time -seconds  Volume -liter or cubic cenitmeter Temperature -Degrees Celcius
Term
 What are the Metric System prefixes and abbreviations?    Hint: You should have 12 of the prefixes and 12 of the abbreviations
Definition
 Trillion - Tera Billion - Giga Million - Mega Thousand - Kilo Hundred - Hecto Ten - Deca   Tenth - deci Hundredth -centi Thousandth - milli Millionth - micro Billionth - nano Trillionth -pico   Abbreviations are just the letter that the prefix starts with except for micro   -u (sort of a cursive u)
Term
 What is Accuracy?
Definition
 the state of correctness
Term
 What is Presion?
Definition
 how specific your answer is, whether it is wrong or right
Term
 What is the Margin of Error?
Definition
 the amount of acceptable error in an expirement
Term
 What is a referance point?
Definition
 an object that is staying in place compared to another object to detect movement
Term
 Whne is an object in motion?
Definition
 when it changes position over time when compared to a referance point
Term
 What is position?
Definition
 the point or area occupied by a physical object
Term
 What is speed?
Definition
 a measurement of how fast something is moving
Term
 What is the equation for speed?
Definition
 Speed= distance/time
Term
 What are some units of speed?
Definition
 miles/hour meters/second etc.
Term
 What is constant speed?
Definition
 When an objects average speed and instantaneous speed are the same
Term
 What is the equation for average speed?
Definition
 Average Speed= total distance/total time
Term
 What is instantaneous speed?
Definition
 an objects speed at any one moment in time
Term
 What are the equations for distance and time?
Definition
 Distance= speed x time   Time= distance/speed
Term
 What is Velocity?
Definition
 the speed and direction of an object
Term
 What is constant velocity?
Definition
 constant speed with no change in direction
Term
 What is the equation for average velocity?
Definition
 average velocity= total distance/ total time
Term
 Velocities can be combined to create what?
Definition
 resultant velocity
Term
 How do you find the resultant velocity of two velocities in the same direction?
Definition
 add the velocities together
Term
 How do you find the resultant velocity of two velocities in opposite directions?
Definition
 subract the smaller velocity from the larger one
Term
 What is acceleration?
Definition
 the rate at which an object's velocity changes
Term
 What does it mean to accelerate?
Definition
 To change velocity
Term
 Is acceleration how much velocity changes?
Definition
 No, it is how fast it changes
Term
 What is the equation for acceleration?
Definition
 Acceleration= change in velocity/time interval
Term
 What is another equation for acceleration?
Definition
 Acceleration=final velocity - initial velocity                          ---------------------------------                 time interval
Term
 What is the acceleration in which velocity increases called?
Definition
 positive acceleration
Term
 What is acceleration in which velocity decreases called?
Definition
 negative acceleration or deceleration
Term
 What are the units of Acceleration?
Definition
 m/s2
Term
 What is inertia?
Definition
 the tendancy of objects to resist a change in motion
Term
 State Newton's First Law of Motion.
Definition
 "An object at rest remains at rest and an object in motion remains in motion at a constant velocity unless acted upon by an unbalaced force."
Term
 What is mass?
Definition
 Mass is the quantity of matter in an object
Term
 What else is mass?
Definition
 the measure of an objects inertia
Term
 What is weight?
Definition
 the force upon an object caused by gravity
Term
 Are weight and mass the same thing?
Definition
 NO!!!!!!!!!!!
Term
 Mass and weight are directly porportional. This means what?
Definition
 That if you double an objects mass, you also double its weight. If you halve an objects mass, you also halve the objects weight
Term
 When does mass change?
Definition
 Never!!!!!!   *This is for inanimate objects*
Term
 Does inertia ever change? How do you know?
Definition
 No, because if mass never changes and it follows an objects inertia, then inertia never changes either
Term
 Would it be easier to push a car on the moon or on earth?
Definition
 It would be the same
Term
 Would it be easier to lift a car on the moon or on earth?
Definition
 on the moon because there is less gravity
Term
 What is volume?
Definition
 the size of an object
Term
 Why are mass and volume not nessisarily porportional?
Definition
 Because of density
Term
 State Newton's Second Law of Motion.
Definition
 "The acceleration of an object is directly porportional to the net force acting on that object, is in the direction of the net force and is inversely proportional to the mass of the object."
Term
 What is the equation for acceleration and how is it directly and inversely proportional?
Definition
 Acceleration=force/mass   If force is doubled, acceleration is doubled. If mass is doubled, then acceleration is halved. Therefore, Force and acceleration are directly proportional and mass and acceleration are inveresly proportional.
Term
 What is a force?
Definition
 Simply, a push or a pull.
Term
 What is net force?
Definition
 it is the sum of the forces acting on an object
Term
 How do you find net force?
Definition
 Add the forces acting in the same direction and subtract forces acting in opposite dirrections.
Term
 What is a vector quantity?
Definition
 A force that involves both magnitude and dictection.
Term
 What is a scalar quantity?
Definition
 Something that involves just magnitude.
Term
 What produces acceleration?
Definition
 The net force.
Term
 What is the unit of force?
Definition
 A Newton
Term
 When is an object in equilibrium?
Definition
 When it is acted upon by balanced forces
Term
 What is a balanced force?
Definition
 When the sum of forces acting on an object equals zero.
Term
 How can a balanced force be created?
Definition
 Two forces must be equal in magnitude and opposiite in direction.
Term
 What happens when two or more forces added together do not equal zero?
Definition
 It is an unbalanced force and acceleration will occur.
Term
 If an object's net force is zero, is it in equilibrium?
Definition
 Yes
Term
 Can an object that is moving be in equilibrium?
Definition
 Yes, if it is moving at a constant velocity.
Term
 What is static equilibrium?
Definition
 When an object is at rest and not accelerating is in equilibrium.
Term
 What is dynamic equilibrium?
Definition
 When an object is in motion and is not accelerating.   In other words, an object that is moving at a constant velocity.
Term
 What kind of equilibrium is a glass on a table in? Why?
Definition
 Static Equilibrium   Because its velocity is 0 m/s and isn't accelerating, therefore the net force on the glass is zero.
Term
 Learn the equilibrium table.
Definition
 Or else.
Term
 What is a normal force?
Definition
 A force produced by a surface an object is resting on, created by the atoms in the surface.
Term
 What is tension force?
Definition
 A force produced by a push or pull.
Term
 What is friction? What is it caused by?
Definition
 a force that occurs when objects slide over each other   caused by atoms clinging together at many points of contact
Term
 What does the magnitude of friction force depend on?
Definition
 the object's weight and the material of the object's   Surface area does not make a difference
Term
 What is the direction of friction force?
Definition
 opposite the direction of motion
Term
 When does friction occur?
Definition
 Once a horizontal force is exerted
Term
 Which has more inertia, a jug filled with air or a jug filled with water? Why?
Definition
 The jug filled with water because it has more mass
Term
 State Newton's Third Law of Motion.
Definition
 " Whenever one object exerts a force on a second object the second object exerts an equal and opposite force on the first."
Term
 Does it matter which object is the action force or reaction force in Newton's Third Law of Motion?
Definition
 No, it can be either.
Term
 What does Newton's Third Law of Motion mean?
Definition
 That forces are equal in strength and opposite in direction.
Term
 When do forces occur?
Definition
 simultaneously
Term
 Can an action force exsist without a reaction force?
Definition
 No.
Term
 Forces always act in ________ .
Definition
 pairs
Term
 Do action and reaction forces act on the same object?
Definition
 No.
Term
 What would happen if action forces and reaction forces acted on the same object?
Definition
 They would cancel each other out and acceleration wouldn't be possible.
Term
 What is the equation for momentum?
Definition
 Momentum=mass x velocity
Term
 Does an object at rest have momentum?
Definition
 No, only moving objects have momentum.
Term
 What is the equation for momentum when direction isn't important?
Definition
 Momentum=mass x speed
Term
 A moving object can have a _________ amount of momentum if mass is __________ and velocity is ________ especially if both are __________.
Definition
 large large large large
Term
 If there is a large amount of momentum in an object, is it easy to stop its motion?
Definition
 No.
Term
 Are momentum and inertia the same thing? Why?
Definition
 No, because Inertia depends on mass only and momentum depends on both the mass and velocity. Furthermore, inertia is involved with both moving and stationary objects while momentum only is involved with moving  objects.
Term
 When does momentum change?
Definition
 WHen an object's mass, velocity, or both change.
Term
 What is required to change momentum?
Definition
 an unbalanced force
Term
 What is an impulse?
Definition
 How much force is being exerted over a certain period of time.
Term
 What is the equation for impulse?
Definition
 Impulse=force x time
Term
 How do you increase an object's momentum as much as possible?
Definition
 Exert a large amount of force over a long period of time.
Term
 Why does it hurt less when you run into a haystack then when you run into a wall?
Definition
 In both cases your  momentum is decreased by the same amount, which means that the impulse needed to stop you is the same. The time of impact is greater for the haystack so the force of impact is greater for the brick wall then the haystack.
Term
 The ________ must be exerted by something _______ to the object.
Definition
 impulse external
Term
 If no force is external to the system of objects, what happens to momentum?
Definition
 It does not change
Term
 Is momentum a vector quantity or a scalar quantity?
Definition
 Vector
Term
 Momentum is always ______ in a collision.
Definition
 conserved
Term
 What is the net momentum of coliding objects after the collision?
Definition
 It is equal to the net momentum before the collision.   Net momentum before = Net momentum after
Term
 What is an elastic collision?
Definition
 a collision where no deformation or heat generation occurs.
Term
 What is an inelastic collision?
Definition
 involves deformation and/or heat generation
Term
 What makes up everything in the universe?
Definition
 matter and energy
Term
 What is matter?
Definition
 Anything that has mass and volume.   His definition: substance
Term
 What is energy?
Definition
 The movment of matter.
Term
 What is the equation for work?
Definition
 Work = force x time
Term
 When calculating work, does the path matter?
Definition
 No, the path taken does not matter only the final distance matters.   Example - If you picked up a rock in the back yard and carried it to the front yard then took it back and put it in the exact place you first picked it up, you have done ZERO work.
Term
 If you lift an object 6 feet off the ground, you've done twice as much work as lifting that object 3 feet off the ground. Why?
Definition
 Because the distance has doubled.
Term
 If you are holding a 500 Newton barbell over your head, how much work are you doing, why?
Definition
 You are doing NO WORK because the distance is zero.
Term
 What are the units for work?
Definition
 Joules
Term
 What is power?
Definition
 a measure of how fast work is done
Term
 WHat is the equation for power?
Definition
 Power = Work done/time interval
Term
 Twice the power means that the same amount of work can be done in _______ the time, or twice the ___________ can be done in the same amount of time.
Definition
 half work
Term
 What is the unit for power?
Definition
 joule/second   - or -   Watts
Term
 How many Watts are in 1 Horsepower?
Definition
 746 Watts
Term
 What is the unit for energy?
Definition
 joules
Term
 What two types of energy are mechanical energy?
Definition
 kinetic energy and potential energy
Term
 What is potential energy?
Definition
 Energy that is stored by an object relative to another object
Term
 What is gravitational potential energy?
Definition
 The potential energy of an object due to an elevated position
Term
 The amount of gravitational potential energy possessed by an object is equal to what?
Definition
 the work done against gravity in lifting it
Term
 What is the equation for Potential energy and why?
Definition
 Work = force x distance Force = mass x acceleration The distance is obviosly the height and acceleration means the acceleration of gravity  SO if you plug in the equation for force  into the equation for work.. you get   Potential Energy = mass x gravity x height
Term
 What is kinetic energy?
Definition
 The energy of motion
Term
 What is the equation for Kinetic Energy?
Definition
 Kinetic Energy = 1/2 of the mass X velocity2
Term
 If velocity is doubled, what happens to the kinetic energy?
Definition
Term
 What is the Work-Energy Thereom?
Definition
 States that   Work = the change in Kinetic Energy
Term
 What is the Law of Conservation of Energy?
Definition
 "Energy can not be created or destroyed; it may be transferred from one form to another, but the total amount of energy never changes."
Term
 What are machines?
Definition
 devices for multiplying or changing the direction of forces
Term
 Why is a lever useful?
Definition
 because you can apply a small force over a large distance to create a large force over a small distance
Term
 What is the equation for efficiency?
Definition
 Efficiency = useful energy output / total energy input
Term
 What is a wave?
Definition
 any disturbance that transmitts energy through matter or space
Term
 When a wave travels, does it take the material through which it traveled with it?
Definition
 No. For example, sound waves often travel through air, but the air does not travel with the sound.
Term
 As a wave travels, what does its energy do work on?
Definition
 Everything in its path.
Term
 What is a medium?
Definition
 a substance though which a wave can travel, and can be a solid, liquid, or gas
Term
 What is a vibration?
Definition
 The back and forth movement of a particle
Term
 How can waves travel?
Definition
 particles vibrate and pass energy to the particles next to them and those particles vibrate and pass energy to particles next to them , and so on and so forth.
Term
 What is a mechanical wave?
Definition
 A wave that requires a medium to travel
Term
 What are some examples of a mechanical wave?
Definition
 sound waves and waves in an ocean or lake
Term
 What is an electromagnetic wave?
Definition
 A wave that requires no medium to travel.
Term
 What are some examples of electromagnetic waves?
Definition
 visible light, microwaves, radio waves, and X rays
Term
 What is a transverse wave?
Definition
 A wave where the particles vibrate up and down perpendicular to the direction the wave is traveling
Term
 What is the highest point of a wave?
Definition
 Crests
Term
 What are the lowest points of waves called?
Definition
 troughes
Term
 What are longitudinal waves?
Definition
 waves where the particles vibrate back and forth along the path that the waves travel
Term
 What is a compression?
Definition
 A section where the particles become crowded together in waves
Term
 What is a rarefaction?
Definition
 A section where the particles are spread out in a wave
Term
 What is amplitude?
Definition
 the maximum distance a wave vibrates from its rest position  the larger the amplitude the "taller" the wave and the more energy it carries
Term
 What is wavelength?
Definition
 the distance between any two adjacent crests or compressions in a series of waves  also the distance between any two adjacent troughs or rarefactions
Term
 What is frequency?
Definition
 the number of waves produced in a given amount of time
Term
 What is period?
Definition
 the time it takes a wave to complete one back-and-forth oscillation
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