Transcript 5.1 Heat Transfer

5.1
Heat Transfer
Vocabulary
A System Is…
• A group of parts that work together to
perform a specific function.
What causes the thunderstorm?
Thunderstorm = result of two different parts of “the
Earth system” interacting
1.Atmosphere: the envelope of
gases that surround the
planet
2. Hydrosphere: made up of all
the water on earth
What is a system?
• A system is a group of parts that work
together to perform a function and produce a
result.
• Usually you have an input and an output.
Weather is caused by:
Constant interaction of hydrosphere and
atmosphere (atmo = vapor / hydro = water)
1.Sun warms gasses in atmosphere and water in
hydrosphere
2.Water evaporates  water vapor
3.Temperatures of atmosphere and water
changes, clouds may build and rain may fall
The condition of the Earths atmosphere at a
particular time and place is called
WEATHER!
What is Temperature?
• All substances are
made up of tiny
particles (atoms and
molecules).
• The faster the
particles are
moving – the more
energy they have!
What is temperature?
• Temperature: measures the
average energy of motion of
particles in a substance
• What is thermal energy?
• Thermal energy: measures the
total energy of motion in the
particles of a substance.
Measuring temperature
• Air temperature is usually measured
with a thermometer
• Thermometer- A device that
measures temperature
–Holds liquid mercury or alcohol
–Air temp increases, liquid inside
increases and expands (rises)
How to calculate thermal
energy?
Q=mc T
Q=Thermal energy
m=mass
C=specific heat
T=Temperature difference
Temperature scalesunits of degrees
• Two scales
1. Celsius
(freezing = 0⁰;
boiling= 100⁰)
2. Fahrenheit
(freezing = 32⁰F;
boiling = 212⁰F)
Check Yourself p. 156
Did your answer look like this?
heat
Energy that transferred
from hotter object to a
colder one (warmer  cooler)
Heat is transferred in 3
ways:
1. Convection
2. Conduction
3. Radiation
radiation
is the direct
transfer of
energy by ray
waves.
ray-diation
conduction
Transfer of heat between two
substances that are in direct contact
with each other.
Energy is transferred when molecules
bump into each other through
contact.
convection
Transfer of heat by
the movement of a
fluid.
Energy is
transferred by the
flow of material.
Examples?
Convection current
p. 158
Check yourself! (p. 158)
• 1. Convection
Contents in side are heated
by convection
• 2. Conduction
heat moves up the pot
by conduction (red )
• 3. Radiation
waves of heat will heat
your hands by radiation
(yellow/orange )
Heat Transfer
Heat Transfer
Heat transfer occurs when a
warm radiator heats a room.
What type of heat transfer
could keep the paper in the
air?
Check yourself!
• Radiation, conduction &
convection work together to
heat troposphere.
Heating the
Troposphere
• Convection currents- the
upward movement of warm
air and the downward
movement of cool air.
• Heat is transferred mostly by
CONVECTION within the
troposphere
• Heat- thermal energy that is
transferred from a hotter object
to a cooler one