Physics core science AQA

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Infrared radiation

Heat can be transferred by convection, conduction and radiation.

Dark, matt objects are best at absorbing heat.

shiny and white objects are best at reflecting heat.

All objects emit and absorb thermal radiation which is also called infrared radiation.

The hotter the object the more infrared radiation it gives out.

Kinetic theory

solids: Have a fixed shape and cannot flow because the particles cannot move from place to place and they cannot be compressed or squeezed because the particles are too close together.

Liquids: They flow and take the shape of the container because the particles can move around each other. they cannot be compressed or squeezed because the particles are too close together.

gases: they can flow and fill the container because the particles can move around quickly in every direction and they can be compressed because the particles are far apart and have place to move.

conduction

metals are a good conductor and non metals are good insulators.

conduction is when heat energy is conducted from the hot end of an object to the cold end of an object.

the electrons in metals can leave their atoms as free electrons.

The atoms left behind create charged metal ions that vibrate when they are together.

The hotter the object the more kinetic energy they have.

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Convection

convection happens when particles in liquids and gases move and take place of particles with less heat energy.

heat energy is transferred from hot places to cool places with convection.

Liquids and gases expand when they are heated.

evaporation and condensation

Evaporation is liquid changing to gas.

Condensation is gas changing to a liquid.

The particles in a liquid have different energies.

Particles in the liquid have a lower average kinetic energy than before evaporation happens.

Factors affecting evaporation and condensation is when the surface area of a liquid is increased or air is moving over the surface of the liquid.

Building

U-value measures how efficient an insulator is.

the lower the U-value is the better the insulator.

The payback time of an energy solution is a measure of how cost effective it is.

(years)=cost of installation (£) / saving per year in fuel cost (£)

Solar panels heat up water. they receive heat energy from the sun.

Cold water is pumped up to the solar panel where it is heated up and transferred to a storage tank.

Advantages of solar panels: solar panel is a renewable energy resource, no harmful polluting gases are produced.

disadvantages of solar panels: only produce hot water when it is very sunny and solar panels don't work at night.

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Specific heat capacity

temp is the a measure of how hot something is.

Heat is a measure of the thermal energy contained in an object

When heat energy is transferred to an object its temp changes due to many factors such as the mass of the object, the substance the object is made from and the amount of energy transferred to the object.

The specific heat capacity of an object is the amount of energy needed to change the temp of 1 kg of the substance by 1 degrees.

You calculate specific heat capacity with the equation E= m x c x theta

Forms of energy

Magnetic (most)

kinetic (kids)

heat ( hate)

light (learning)

gravitational potential (g)

chemical (c)

sound (s)

electrical (e)

elastic potential ( energy)

nuclear (names)

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