P1 - Work done by a force, Calculating Power, Cooling of buildings

what does work done mean

Whenever energy is transferred from one store to another work is done

what does mechanical work involve?

using force to move an object

what does electrical work involve?

A current transferring energy

what is are the units for force

newtons

define power

the rate at which work is done (energy is transferred)

what is power measured in

Watts (W)

1 watt is an energy transfer of...

1 joule per second

define thermal conductivity

The ability of an object to transfer heat. the higher the thermal conductivity of a material, the higher the rate of energy transfer across that material

how many layers are modern houses built from

2

what are the layers modern houses in the uk are made from called

internal breezeblock wall, external brick wall

what sits inbetween the walls?

a cavity

what do builders pack the cavity with to avoid major heat loss

insulating material with a very low thermal conductivity

what type of thermal conductivity do single glazed windows have

high thermal conductivty

what do builders do to trap heat loss via windows

build double glazed windows

how do we prevent thermal energy escaping through the roof of the house

loft insulation

how do we reduce the thermal energy transfer in a house

construct the building using materials with a low thermal conductivity

build a house with thick walls