Heat Flashcards
Define “Heat”
Heat is a form of thermal energy possessed by hot bodies measured in joules.
Define “Temperature”
Temperature is a measure of how hot or cold something is measured in degrees Celcius
Give an example of something that is hot but does not contain a lot of heat energy.
a sparkler spark very hot but is so small it does not contain much energy.
What are the three methods of heat transfer?
Conduction, Convection and Radiation
Which forms of heat transfer require matter?
Conducton and Convection
Which form of heat transfer does not require matter?
Radiation
Use the particle theory to explain heat.
When an object is heated its particles move more rapidly because they have more energy
Explain, using the particle theory, how hot objects transfer heat to cold objects.
The rapidly moving particles of the hot object transfer some of their energy to the cooler object.
What is the coldest temperature possible?
Minus 273 degrees Celcius. All motion of particles stops at this temperature (absolute zero)
What three variables govern the amount of heat gained or lost by an object?
Its mass, the change in temperature and what it is made of.
Heat is transferred in liquids and gases by _____.
Convection
Give an example of a hot object transferring heat to a cooler substance.
An electric kettle element is heated and this heats the water.
Heat is transferred in a solid by ________.
Conduction
Use the particle theory to explain why heat is moved by convection in gases and liquids
The particles in liquids and gases can move which allows heat to flow in the liquid or gas.
Heat is transferred in a vacuum by _______.
Radiation
In what form is heat radiated through a vacuum?
Waves
What three things can happed to heat radiation when it strikes matter?
Radiation can be absorbed, reflected or transmitted by matter.
Use the particle theory to explain how heat is moved by conduction in a solid.
The particles in a solid are fixed and have limited movement. Heat moves by particles vibrating against their neighbouring particles. Some solids are better conductiors than others.
Transmitted heat p______ through material
passes
Reflected heat b_______ off material
bounces
Define “Heat Conductor”
Substances that conduct heat well. Most metals are good conductors.
Define “Insulator”
Insulators are poor conductors of heat.
What is the colour of material that best absorbs heat?
Dark colours
What is the colour of material that best reflects heat?
Light colours
