33 terms

# Heat and Temperature

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Temperature
related to the random motion of atoms and molecules in a substance. measure of the average translational kinetic energy per molecule in a substance. measured in degrees.
Heat
the energy transfer from one object to another because of a temperature difference. measured in joules
Internal Energy
grand total of all energies inside a substance. rotational kinetic energy, kinetic energy, potential energy.
Calorie
the amount of heat required to change the temperature of 1 gram of water by 1 Celsius degree.
Specific Heat Capacity
quantity of heat required to change the temperature of a unit mass of the substance by 1 degree.
Thermal Expansion
when temperature of a substance is increased, its molecules or atoms jiggle faster and move further apart resulting in the expansion of the substance.
Absolute Zero
the lowest possible temperature that a substance may have- the temperature at which molecules of the substance have their minimum kinetic energy.
Conduction
the transfer of heat energy by molecular and electron collisions within a substance. especially a solid.
Convection
the transfer of heat energy in a gas or liquid by means of currents in the heater fluid. the fluid moves, carrying energy with it.
the transfer of energy by means of electromagnetic waves.
Newtons Law of Cooling
the rate of loss of heat from an object proportional to the temperature difference between the object and its surroundings.
Evaporation
the change of phase from liquid to gas
Condensation
the change of phase from gas to liquid.
Boiling
rapid evaporation that takes place within a liquid as well as at its surface.
Hertz
the SI unit of frequency. 1 hertz equals 1 vibration per second.
Period
the time in which a vibration is completed. the period of a wave equals the period of the source, and is equal to 1/frequency.
Standing Wave
a stationary wave pattern formed in medium when two sets of identical waves pass through the medium in opposite directions.
Frequency
for a wave, the number of crests that pass a particular point per unit time.
Wavelength
the distance between successive crests, troughs, or identical parts of a wave.
Wave Speed
the speed with which waves pass a particular point
wave speed=wavelength x frequency
Infrasonic
a sound that has a frequency too low to be heard by the normal human ear.
Ultrasonic
a sound that has a frequency too high to be heard by the normal human ear.
Refraction
bending of sound or any wave caused by a difference in wave speeds.
Natural Frequency
a frequency at which an elastic object naturally tends to vibrate if it is disturbed and the disturbing force is removed.
Resonance
the response of a body when a forcing frequency matches its natural frequency.
Interference
a result of superposing different waves, often of the same wavelength. constructive interference results from crest to crest reinforcement; destructive interference results from crest to trough cancellation.
Beats
a series of alternative reinforcements and cancellations produced by the interference of two waves of slightly different frequencies, heard as a throbbing effect in sound waves.
What is most closely related to the average kinetic energy of translational motion of the molecules in an object?
the temperature of the object
Heat flows from the Sun to the Earth because....?
the Sun has a higher temperature than the Earth.
How much heat ( in "calories" ) would it take to change the temperature of 3 grams of the water ( liquid ) from 0 degrees C to 4 degrees C?
12 calories
Heat flows from the Sun to the Earth by the process called....