physics -heat

What is temperature

Temperature is the measure of the hotness or coldness of a body.

What are thermometric properties

Thermometric properties are any physical properties that change measurably with

temperature.

What Is specific latent heat

Specific latent heat is the amount of energy needed to change the state of 1kg of that substance without changing it's temperature

What is the specific heat capacity

The heat energy needed to change the temperature of 1kg of a substant by 1K

What is conduction

the movement of heat energy through a substance by the passing of molecular vibration from molecule to molecule without any overall motiom of the substance

convection

the transfer of heat through a fluid by means of circulating currents of fluid caused by the heat

radiation

the transfer of heat energy friim one place to another in the form of electromagnetic waves

u value

the amount of heat lost per second through 1m² of the structure when a temperature difference of 1k is maintained betweeen its ends

what is a solar constant

the average amount of suns energy falling per second perpindicularly on 1m² of the earths atmosphere. 1.35kW/m²

whats the difference between heat and temperature

heat is a form of energy and te,perature is the measure of the hotness or coldness of a body

give an advantage of using kelvin

temperatures are always positive

what is a thermometer

an instrument used to measure temperature

onwhat thermometric proporties is the mercury based thermometer

length or height or volume of a column of mercury

name another type of thermometer and state its thermometric proporty(not mercury based)

an electrical resistance thermometer

thermometric proporty is resistance

on what thermometric proporty is the thermocouple based

emf

give an advantage of using a thermocouple instead of a mercury-in-glass thermometer

it is much more durable and will not be damaged

it has a wider temperature range

it can measure temperature inaccessible to a mercury-in-glass thermometer

name a thermometric property

emf,length,colour, pressure of a gasat constant volume, volume of a gas at constant pressure

why is it necessary to have a standard thermometer

because different thermometers have different thermometric properties and give different readings at the same temperature

what is the name given to the tendency of water to circulate as it is heated

convection

explain why heat does travel through solids by means of convection

the particles in a solid cannot move freely throughout the solid

how can u-vaule be reduced

put thicker insulation in the walls, fill the cavity between walls with insulating foam

what is the advantage of a low u-value

less energy will be lost from the building when it is colder outside

how is energy transferred from the sun to the earth

by means of radiation 

what is heat capcaity

the amount of heat energy neede to change its temperature by 1k (J)

state the principle that underlies the operation of an electrical storage heater

a storage heater consistss of an electric heater surrounded by bricke of large heat capcity. the bricks are heated by night when electricity is cheaper and store a large quantity of energy. during the day the bricks slowly release their energy to the room

what is latent heat

the heat enrgy neede to change its state without a change in temperature

why does the temperature of an athlete reduce when she perspires

as the persipiration evaporates it takes the latent heat from the athlete and her temperature falls

what is a heat pump

a device that transfers heat from a cooler region to a warmer one

explain why snow is slow to melt as the air rises above 0C

because the enrgy needed to change the  state of snow is very large