SCIENCE - temperature, heat & heat transfer.

Heat vs. Temperature

TEMP = can be both hot and cold measured in Celcius or Farenheit to communicate the heat or absence of it world wide.
(the average kinetic energy of a group of particles)

HEAT = is our interpretation of a temperature based on our surroundings
(int he summer air conditioner at 18 is cold but in the winter we heat our houses to 18)
(the energy that flows from hot to cold constantly being transferd)

2 most important types of energy for this unit

heat energy
kinetic energy

What does 0 Kelvin mean?

absolute zero (no kinetic energy)

Brownian motion

random movement due to particles colliding

0 Celsius = _?_ Kelvin

273.15 K

thermal equilibrium

when two objects are at the same temperature and no heat flows

measuring the uncertainty

1/2 of the smallest increment
(ruler smallest increment equals 1mm so uncertainty = 0.5mm)

conductors are ____

are able to transfer conduct heat and electricity. (metals)

insulators are ____

poor conductors of energy transfer;
examples are wood, plastic, foam, paper and rubber.

density =

mass/volume
higher volume = lower density

Difussion

Molecules move from an area of higher concentration to an area of lower concentration

convection

Process by which, in a fluid being heated, the warmer part of the mass will rise and the cooler portions will sink.

radiation

Energy that is radiated or transmitted in the form of rays or waves or particles.

Condcution

the process by which heat or electricity is directly transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.

what are Bimetals

Bimetals are materials made from two different metals that are bonded together. They are often used in temperature-measuring devices because of their property to bend when heated or cooled, due to the different expansion rates of the two metals.

what happens when a substance is heated

the molecules move farther apart and move at a higher rate

convection in weather

On a summer day, the streets can get very hot. This heats the air above the streets and makes it rise up. At the same time, cool air begins to sink. This movement of air caused by heating and cooling is called convection.

Best absorbers and emitters are...

Dark, matte surfaces
(bc they absorb most light and heat and do not reflect it)

worst absorbers and emitters are..

shiny, silvery surfaces
(because they reflect all most light and heat)

IR stands for what?

Infra red radiation

how does global warming work and what is causing more radiation to be absorbed?

greenhouse gasses trap heat from the sun keeping it within or atmosphere.
increase of global temp = increase of radiation absorption