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Everything has heat, even cold stuff
Molecules in cold things move slower than molecules in warm things
More molecules = more heat energy
Convection Current
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Less dense on top, more dense on bottom
Cycle
Matter- the stuff that makes up everything
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To change matter it needs energy
Atoms- tiny units bond together to make molecules (the building blocks of matter)
Kinetic energy- energy of movement
The faster the atoms go the more heat, farther they get apart- expand
Temperature is not the same as heat
Temperature is a measurement- measures how fast the molecules move
Heat is a form of energy
If molecules stop moving then there is no temperature- never happened
When it feels cooler, heat is being drained from you
Shivering helps you warm up
Heat transfer: hot always goes to cold
3 types of heat transfer: convection, conduction, radiation
Molecules don’t want to be different, so they transfer heat to each other to be the same temperature
Radiation- is how heat energy moves in waves through space from the sun to the Earth
Sun is the ultimate energy source
Photosynthesis- plants store energy from the sun- called chemical energy
Methods of Heat Transfer
Two types of energy- Kinetic and Potential
Potential energy- stored energy
Chemical energy- energy stored in food, batteries, and fuels
Kinetic energy- energy an object has due to its motion
The movement of particles is a form of kinetic energy
Heat is internal energy that is transferred from one object to another as a result
of a difference in temperature between the two
Internal energy = potential + kinetic energy
Energy is measured in Joules (J)
All things will return to room temperature by either getting heat or giving heat
Heat, energy, and temperature
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Heat is energy transfer
Temperature measures kinetic energy
Object not hot or cold depending on particles vibrating
Internal energy = potential energy + kinetic energy
Energy is measured in Joules
Celsius or Kelvin scales
Heat flows from hot to cold
Conduction
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Movement of heat through solids
Particles vibrating = kinetic energy
Particles pass on kinetic energy
Metals are good conductors
Poor conductors used as insulators
Convection
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Convection occurs in fluids (liquids and gases)
Particles move faster and further apart
Hot air rises
Cool air replace hot
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Convection currents occur when heated fluid rises
Cooler fluid moves into replace it
Radiation
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Radiation occurs in a vacuum
The sun source of radiated heat
Heat radiation- electromagnetic waves infrared
All objects absorb and emit radiation
Black radiates better than white