# Shared Flashcard Set

## Details

Test 5
notes
59
Physics
10/18/2015

Term
 The energy of a system increases when what is done on that system?
Definition
 work
Term
 Under what condition is work positive?
Definition
 if force and motion are in the same direction (W=deltaKE)
Term
 What must an object be doing to have kinetic energy?
Definition
 moving
Term
 What states that the force necessary to elongate a spring a small distance (x) is proportional to the elongation (F=KX)?
Definition
 Hooke's Law
Term
 In F=KX, what is K?
Definition
 the spring constant and is an indication of the spring's stiffness
Term
 What is energy stored in a system as a result of the gravitational force between the object and Earth? (PE=mgh)
Definition
 gravitational potential energy
Term
 Why is the sum of KE and PE constant at all times?
Definition
 no work is done on the system by any external forces
Term
 What is stored energy in pulled strings, rubber balls, rubber bands, slingshots, and trampolines?
Definition
 elastic potential energy
Term
 What is a result of electromagnetic interactions among the atoms in the material?
Definition
 elasticity
Term
 What are materials that can be permanently stretched?
Definition
 plastic deformations
Term
 Almost all solids can be stretched or compressed slightly, but what can be bent and are designed to do so in a controlled and predictable way?
Definition
 springs
Term
 Who recognized mass as a form of potential energy?
Definition
 Einstein
Term
 In which theory is the rest energy equal to the object's mass times speed of light squared?
Definition
 theory of relativity
Term
 What states that in a closed, isolated system, energy cannot be created nor destroyed but can be changed?
Definition
 Law of Conservation of Energy
Term
 What is the sum of KE and PE if no other energy has occurred (usually thermal energy)?
Definition
 mechanical energy
Term
 the kinetic energy in a system does not change
Definition
 elastic collision
Term
 KE energy decreases
Definition
 inelastic collision
Term
 What is almost always conserved in a collision?
Definition
 momentum
Term
 What is conserved only in elastic collisions?
Definition
 energy
Term
 Momentum is what makes objects do what?
Definition
 stop
Term
 A hot object has more thermal energy that what?
Definition
 cold objects
Term
 average kinetic energy of particles an object (this does not depend on the number of atoms in an object)
Definition
 temperature
Term
 What is proportional to the number of particles in a an object?
Definition
 thermal energy
Term
 What is temperature measured using?
Definition
 a thermometer
Term
 What is the transfer of KE when particles collide (usually direct contact)?
Definition
 conduction
Term
 What is the rate of energy flow between two objects is equal and objects are at the same temperature?
Definition
 thermal equilibrium
Term
 Who devised a temperature scale based on the properties of water?
Definition
 Anders Celsius
Term
 When did Anders Celsius devise his temperature scale?
Definition
 1741
Term
 What is the upper limit of temperature?
Definition
 no limit known
Term
 What is the interior of the Sun?
Definition
 1.5 x 10^7 Celcius
Term
 lowest possible temp of all matter
Definition
 absolute zero
Term
 Absolute zero in Kelvin
Definition
 0K
Term
 Absolute zero in Celcius
Definition
 -273.15
Term
 Absolute zero in Fahrenheit
Definition
 -460
Term
 Freezing point of water in Celsius
Definition
 0
Term
 Freezing point of water in Fahrenheit
Definition
 32
Term
 Freezing point of water in Kelvin
Definition
 273
Term
 Boiling point of water in Celsius
Definition
 100
Term
 Boiling point of water in Fahrenheit
Definition
 212
Term
 Boiling point of water in in Kelvin
Definition
 373
Term
 energy that always flows form the hotter object to a cooler object, energy that is transferred between objects
Definition
 heat
Term
 motion of fluid in a liquid or gas caused by temperature differences
Definition
 convention
Term
 does not depend on presence of matter; transfer of energy by electromagnetic waves. these waves carry the Sun's energy through the vacuum of space to Earth
Definition
Term
 amount of energy that must be added to a material to raise the temp of a unit mass by 1 temp unit
Definition
 specific heat
Term
 device used to measure changes in thermal energy (carefully insulated and contains a known mass of cold water0
Definition
 calorimeter
Term
 Changes in states are what kind of changes because the composition of the matter is not changed, only its phase?
Definition
 physical changes
Term
 the change from a solid to a liquid
Definition
 melting point
Term
 What doesn't rise as liquid boils?
Definition
 temperature
Term
 amount of energy needed to melt 1 kg of a substance
Definition
 heat of fusion
Term
 What is the heat of fusion of ice?
Definition
 3.34 x 10^5 J/kg
Term
 thermal energy needed to change 1 kg of liquid to a gas
Definition
 heat of vaporization
Term
 What is the heat of vaporization of water?
Definition
 2.26 x 10^6 J/kg
Term
 What will increase the boiling point and decrease the freezing point of water?
Definition
Term
 change in thermal energy of an object is equal to the heat that is added to it minus the work done by the object (restates the law of conservation of energy)
Definition
 first law of thermodynamics
Term
 device that continuously converts thermal energy to mechanical energy
Definition
 heat engine
Term
 measure of disorder in a system
Definition
 entropy
Term
 What is the change of entropy equal to?
Definition
 the heat added divided by temperature in K
Term
 natural processes tend to go in a direction that maintains or increases the total entropy of the universe. Things will grow more and more disorderly unless some action is taken to keep them in order
Definition
 2nd law of thermodynamics
Term
 What is created from all interactions (this takes away from the efficiency of a system)?
Definition
 waste heat
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