Physics: Thermal Energy

entropy

the amount of disorder in a system

usually increases

the disorder in a system left to itself (no work done) will a. usually increase b. can decrease c. always remains the same

absolute zero

the lowest possible temperature on the Kelvin scale where all molecules would stop

thermodynamics

the study of the flow of heat energy

1st law of thermodynamics

this states that energy is never created nor destroyed:heat lost by an object is gained by another

2nd law of thermodynamics

this states that heat will always flow from hot objects to cold objects, efficiency is always less than 100%, and total disorder can never decrease

3rd law of thermodynamics

this states that it is impossible to achieve a temperature of absolute zero

temperature

two objects in thermal equilibrium have the same

temperature difference

what causes heat to flow?

aluminum because it is a better conductor, they are the same temperature

when a piece of aluminum and a piece of wood are at room temperature, which feels colder?

internal energy and temperature

when mechanical work is done on a system, there can be an increase in its a. internal energy b. temperature c. internal energy and temperature d. none

aluminum

which of the following is the best conductor of heat? a. wood b. water c. aluminum d. plastic

the ocean

Which of the following things has the most thermal energy? a. the ocean b. a camp fire c. a hot oven d. a hot water bottle

thermometer

a capillary tube with a liquid that is calibrated to measure temperature

refrigerator

a device that uses work to move heat from a cold place to a hotter one

radiation

a transfer of heat energy through space by means of electromagnetic waves

celsius

a unit of measurement that was once called Centigrade because there are 100 degrees between the freezing point of water in this scale

fahrenheit

a unit of temperature in which the freezing point of water is 32 degrees

radiation, conduction, convection

describe the three ways heat energy can be transfered

heated and expands (thermal expansion)

how does a thermometer work?

controls temperature mixing hot and cold air

how does a thermostat work?

equal to

if 25 g of hot water are added to 35 g of cold water, the heat lost by the hot water is (less than/greater than/equal to) the heat gained by the cold water

heat engine

A device that uses heat to do work and but is not 100% efficient and expels excess heat

temperature

A measure of the average molecular kinetic energy

conduction

A method of energy transfer between objects in contact due to temperature difference

convection

Heat that is transferred by movement of a fluid

thermal energy/internal energy

The total energy of the motion of the molecules contained in an object

heat

Thermal energy in motion

0th law of thermodynamics

This states that when two objects are in contact, heat will flow until they are in thermal equilibrium

heat should flow out

on a winder day, does cold flow into the house through the windows?