physics heat test

temperature

measure of quantity of heat of cold In an object

what is cold?

the absence of heat

what happens to molecules when temp increases?

molecules speed up, spread out

what happens to molecules when temp decreases

molecules slow down and condense

less likelihood for movement and fewer collisions

how fast would the molecules inside of a desk be moving

slowly

American scale for measuring temp

Fahrenheit, 32 degrees freezing and 212 boiling

metric scale for measuring temp

celsius/centigrade, 0 freezing 100 boiling

scientific scale for measuring temperature

Kelvin

absolute coldest

absolute zero, -273 degrees C

heat

energy transfer from one place to another

what happens when you touch a stove with your hand

heat transfers from the stove to your hand

how does heat travel

from high to low/more to less heat

what happens when you walk outside in the cold

heat leaves your body and you feel cold

thermal energy

temperature measure of internal energy molecules in body

thermal contact

transfer of energy until equilibrium

why doess it feels warmer to walk on carpet than to walk on tile

specific heat

thermal equilibrium

don’t feel hot or cold, for every one molecule in a direction there is another equal

what does thermometer measure

• measure how much heat is present

• tells temp of itself once hit equilibrium

requirements for measuring heat

mass and material

common American unit for measuring heat

calorie

metric measurement of heat

Joule

tile vs carpet

tile takes your heat faster

specific heat

amount of energy required to raise unit of mass per degree in Celsius

another name for specific heat

thermal inertia

thermal inertia

how likely temp is to stay the same when acted upon

water specific heat

high specific heat, not likely to change or give off a lot of energy

iron

low specific heat

high specific heat

not likely to change

low specific heat

gain/lose heat easily

water as cooling and heating agent

steals your heat without changing

antifreeze

water-based engine coolant

water regulates climate

currents carry warm water that cools off at pole and cools water on coasts

what city has mild temp year round

san francisco

what city has cold winters and warm summers because of water

washington dc

where is water most dense

4 degrees C

what happens to water at 4 degrees C

it sinks

how do lakes not freeze

water sinks at 4 C, keeps bottom from freezing

thermal expansion

materials expand at different rates

why are there lines in concretes

to manage cracks from expansion

asphalt

expants more than concrete

bimetallic strips

in thermostat, expand and contract at different rates to detect temperature and control air

thermometer glass expanding

glass expands slower than the liquid, so the liquid rises to show temp

good conductors

transfer heat easily

metals

low specific heat

iron conductivity

iron more conductive than aluminum because of its mass and specific heat

most conductive material

silver

commonly used conductive material

copper because it’s cheaper

good insulators

high specific heat, don’t transfer easily

examples of good insulators

air, wood, carpet, wool, fabric, cork

air betwween fibers

why do we insulate homes

to keep heat out during summer, in during winter

convection

heat moving currents within a fluid (liquid or gas)

magma in mantle of earth

heat molecules rise, cool down, condense, then sink

forms magnetic field that blocks sun’s harmful radiation - solar flare

what is aurora borealis evidence of

solar flare

what are winds result of

molecules moving

how are winds created

heat rises, cooler air enters, the difference of temperatures creatives a vacuum

mountains example with wind

windward side is lush from moist air, leeward side (faces land) dry and desert

Chicago “Windy city”

sits on a great lake

what do fans do

circulate air in homes

convection over

has fans and heats food faster and more evenly

radiant energy

transmitting energy through waves

what emits radiant energy

the sun or any star that emits light

flamges

heat radiates off fire

electromagnetic spectrum

relationship between temperature and wavelengths

shorter wavelengths

higher energy and temp

longer wavelengths

lower temperature

what does asphalt absorb

radiant energy

what do mirrors reflect

radiant energy

darker materials

absorb

lighter materials

reflect

emission of radiation

good absorbers = good emitters

why would a white coffee cup keep drink hot

it reflects heat

how would a fireplace keep warm without a fire

it’s dark and would absorb and emit heat

newtons law of cooling

further away the temper of 2 objects, faster they will try to meet the middle

warm or cold water to quickly make ice

warm

global warming

atmospheretraps radiant from going back into space

greenhouse effect

traps energy, warms earth

molecules in a gas

moving quickly and spread out

molecules in a solid

slow and condenses

evaporation

• liquid to gas

• increase in molecule activity

• cooling process - remove heat from obj (liquid takes heat)

how is sweating a cooling process

the sweat evaporates and takes the heat, cools US off

examples of evaporation

steam, dogs pants, pond water evaporating, mist on the ground after rain

condensation

• gas to liquid

• molecules slow down and become liquid

• warming process - giving energy away to surface being struck

condensation on a cold drinking glasss

humidity slows down as it hits the container and settle

clouds forming

condensation

molecules slow down and stick together

frosty window

condensation

cold outside, warm inside, molecules strike window and slow down

boiling

liquid to gas below the surface of water

bubbles rise and release gas into atmosphere at surface

cooling process - taking energy away from something

what does pressure increase

boiling point

pressure cooker

temperature increases and food cooks fasters

high altitude pressure

pressure is lower

pressure deep in the ocean

higher

freezing

• liquid to solid

• molecules slowing down and give energy away

• warming process

how to lower freezing point

put salt or sand

condensation and evaporation equilibrium

bowl of still water, happening at same rate

boiling and freezing equilibrium

taking out air to decrease pressure

melting and freezing equilibrium

regelation

regelation example

making a snowball, ice cube and wire experiement

boiling and freezing at same time example

freeze dried foods

melting

cooling process, taking energy

solid to liquid/gas

heat being put in

gas to liquid to solid

heat removed