Heat, energy and energy transfer

a form of energy measured in joules

adding heat will cause temperature to rise

increases temperature causes expansion of material vs contraction changes state of a substance (solid-liquid-gas)

a metal ball on a skewer, a ring with the same diameter as the metal ball. Heat the metal ball over the bunsen burner, it won’t fit through the ring. Cool it down in water, it will fit.

a beaker with water on a stand over a bunsen burner. a conical flask inside the beaker with alcohol, and a glass tube coming up from the conical flask. As the water heats, the level of alcohol in the glass tube will rise because it has expanded. thermometers with alcohol or mercury use this

it expands when it freezes - makes water pipes burst

beaker with water on bottom. Conical flask upside down above beaker, with glass tube coming out of it into the water. heat the conical flask from the outside with a bunsen burner- bubbles should be seen. As it cools down, the glass tube will suck up water because the air inside is contracting.

conduction, convection, radiation

the movement of heat energy through a substance without any overall movement of the substance itself

add hot water to a tank. on the other side of the tank, attach equal lengths of materials of the same diameter. with vaseline, stick a tack on each one. The first tack to fall off bc the vaseline melted is the best conductor of heat - copper.

the movement of heat energy through liquids and gases due to the motion of the substance itself

conical flask with a lid on top. a little bit of dye on the bottom and some water. over a stand on a bunsen burner . as it heats up, the convection currents can be seen as the hot water moves up and colder water sinks down the sides.

cause the north atlantic drift which keeps seawater near ireland warm and prevents harsh winters. however it will reverse if global warming happens -causes wind. if wind is warmed, violent storms will result

a box with two chimneys on right and left. candle at bottom heats air, risinf out og right chimney. cool air comes down left chimney-convection currents can be seen with smoke from a piece of smouldering string held down the left chimney

the transfer of heat energy via radiation waves that can travel through a vacuum.

a type of light known as rays of infrared radiation

thermal imaging cameras detect warm objects (humans) in search and rescue operations. -energy travels from sun to earth

black objects are good at absorbing and losing heat energy. white objects aren’t. If more snow and glaciers melt, more heat will be absorbed by the Earth from the Sun as there are less white objects. This causes more global warming

two flasks one white one black filled with hot water- note temp every 5 minutes. Black can better at losng heat - a better radiator of heat

heat energy causes vibrating particles to pass on heat energy to other particles - on solids

warm particles rise, cooler particles fall to take their place : liquids, gases

all warm objects release radiation as rays of infrared lights - all substances