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All things are made up of matter

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use solar collectors: devices that absorb radiant energy from the sun ... solar collectors are usually black and covered with glass to reduce energy loss ... – PowerPoint PPT presentation

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Title: All things are made up of matter


1
  • All things are made up of matter
  • Matter is composed of very small particles that
    cannot be seen with the eye.
  • These small particles are always in motion

2
Temperature
  • a measure of the average kinetic energy of the
    particles in a sample of matter.
  • We know that temperature changes, so the kinetic
    energy of the particles must change also.
  • The law of Conservation of Energy tells us that
    energy cannot be created or destroyed.

3
Thermal Energy
  • the total energy of the particles in a material
  • includes both kinetic and potential energy
  • Thermal Energy of a material depends on the total
    energy of its particles,
  • not the kinetic energy of the object itself

4
What effects the amount of Thermal energy
  • the more mass, the more particles, therefore more
    thermal energy.
  • different materials have different thermal
    energies

5
Heat
  • the flow of thermal energy due to a temperature
    difference between two objects.
  • Heat flows from HOT to Cold
  • Heat is measured in calories or joules
  • Calorie the quantity of heat needed to increase
    the temperature of 1 gram of water by one degree
    Celsius.

6
Specific Heat
  • the amount of energy needed to raise the
    temperature of 1 kg a material 1 Kelvin.
  • measured in joules per kilogram per Kelvin
  • J/(g . C)
  • Different materials have different specific heats
    therefore, it takes a different amount of energy
    to raise two materials one C
  • Ex.
  • You can burn your feet walking on concrete to get
    in a pool and be comfortable when you get in it.

7
Common Specific Heats
  • silver 0.24
  • glass 0.50
  • aluminum 0.90
  • steam 1.7
  • wood 1.8
  • ice 2.1
  • grain alcohol 2.4
  • water 4.18

8
Calculating Thermal Changes
  • You cannot measure changes in thermal energy, but
    they can be calculated.
  • To do this you use a special instrument called a
    calorimeter
  • A calorimeter is used to measure an increase in
    water temperature as a basis for finding thermal
    change.

9
To find the thermal change use the Equation
  • Change in Thermal energy mass x change in
    temp. x specific heat
  • Q m x ?T x C
  • Q change in thermal energy
  • m mass of material
  • ?T change in temperature
  • C specific heat of material

10
Change in Temperature
  • ?T is found by subtracting initial temperature
    from final temperature.
  • ?T Tfinal Tinitial
  • If ?T is a negative(-), Q is also negative(-)
    because the system has lost energy.
  • Example
  • A 32 g silver spoon cools from 60?C to 20?C.
    What is the change in its thermal energy?

11
In what ways do people use Thermal Energy in
their lives???
  • Thermal energy is used in many different forms in
    society.

12
Thermal Energy on the Move
  • Conduction the transfer of energy through matter
    by direct contact of particles.
  • the particles collide
  • the momentum of the particles is transferred from
    faster to sloweroccurs in all states of matter
  • is best in solids, because the particles are so
    close

13
Thermal Energy on the Move
  • Convection the transfer of energy by the bulk
    movement of matter.
  • used with fluids any material that flows
    (liquids gases)
  • when heat is added to a fluid, the particles
    begin to move faster
  • the particles are free to move farther apart or
    expand
  • Ocean Currents are a global form of convection
  • winds assist the currents with convection of
    their own.

14
Thermal Energy on the Move
  • Radiation the transfer of energy in the form of
    waves.
  • energy that travels by radiation is often called
    Radiant energy.
  • the suns rays travel as radiant energy
  • only a portion of these rays are absorbed by the
    earth
  • only the radiant energy that is absorbed becomes
    thermal energy
  • any object warmer than 0 K emits radiation.

15
Conventional Heating Systems
  • All heating systems must have a source of
    energy, such as fuel or electricity

16
Types of Heating Systems
  • Radiator Systems
  • a radiator is a device with a large surface area
    designed to heat the air near it by conduction
  • convection currents then currents then circulate
    the heat to all parts of the room
  • energy sources can be electricity or fuel

17
Types of Heating Systems
  • Forced-Air Systems
  • A blower is used to move warmed air through a
    series of large pipes (ducts) to openings (vents)
    in each room
  • Warm air circulate by convection, cool air
    returns to the furnace to be reheated
  • Energy sources can be electricity or fuel

18
Types of Heating Systems
  • Electrical Heating Systems
  • heating coils are enclosed within floors or
    ceilings and are heated by electrical energy.
  • nearby air is warmed by conduction and people and
    materials in the room are warmed by radiation
  • energy sources are entirely electrical

19
Types of Heating Systems
  • Solar Heating
  • solar energy can be used to heat buildings

20
Types of Solar Heating
  • Passive Solar Heating
  • use no fans or mechanical devices to transfer
    heat from one are to another.
  • Southside wall is full of windows other walls are
    well insulated with few windows
  • heat is absorbed by the walls and objects in the
    room
  • as the room cools, the heat that was absorbed is
    released to heat the room

21
Types of Solar Heating
  • Active Solar Heating
  • use solar collectors devices that absorb radiant
    energy from the sun
  • the radiant energy that is absorbed, heats water
    or air which is pumped throughout the house.
  • solar collectors are usually black and covered
    with glass to reduce energy loss
  • the pipes are located right underneath of the
    collectors.
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