Energy and Matter. In which state of matter does conduction of heat occur? Why?
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Transcript of Energy and Matter. In which state of matter does conduction of heat occur? Why?
Energy and Matter
Energy and MatterIn which state of matter does conduction of heat occur? Why?
In which state of matter does conduction of heat occur? Why?
Solids – because thermal conduction requires the collisions between the molecules of a substance.
Energy and Matter
Which are examples of good conductors of heat?
a.metalsb.non-metalsc.waterd.air
Energy and Matter
Which are examples of good conductors of heat?
a.metalsb.non-metalsc.waterd.air
Energy and Matter
Which are examples of poor conductors of heat?
a.copperb.aluminumc.irond.Styrofoame.glass
Energy and Matter
Which are examples of poor conductors of heat?
a.copperb.aluminumc.irond.Styrofoame.glass
Energy and Matter
Convection occurs in both _________ and ________ states of matter.
Energy and Matter
Convection occurs in both liquid and gas states of matter.
Collectively called “fluids”
Energy and Matter
Which state of matter is completely compressed, retains its shape, and represents the lowest form of kinetic energy among its molecules?
Energy and Matter
Which state of matter is completely compressed, retains its shape, and represents the lowest form of kinetic energy among its molecules?
solids
Energy and Matter
Which state of matter can be compressed further, its molecules completely dissociate to fill any container and represents one of the state with the highest kinetic energy.
Energy and Matter
Which state of matter can be compressed further, its molecules completely dissociate to fill any container and represents one of the state with the highest kinetic energy. gas
Energy and Matter
Which of the following statements is NOT true of liquids.
a.its molecules are loosely associated
b.particles have moderate kinetic energy
c.easily compressed
Energy and Matter
Which of the following statements is NOT true of liquids.
a.its molecules are loosely associated
b.particles have moderate kinetic energy
c.easily compressed
Energy and Matter
Which best describes a thermal insulator?
a.impedes the flow of heatb.absorbs heat readilyc.has low specific heatd.most metals are insulators
Energy and Matter
Which best describes a thermal insulator?
a.impedes the flow of heatb.absorbs heat readilyc.has low specific heatd.most metals are insulators
Energy and Matter
Thermal expansion occurs when a.water freezesb.materials are heatedc.kinetic energy decreasesd.potential energy increases
Energy and Matter
Thermal expansion occurs when a.water freezesb.materials are heatedc.kinetic energy decreasesd.potential energy increases
Energy and Matter
What is the boiling point of water in Celsius degrees? (Use proper units)
Drop of a Bullet
Energy and Matter
What is the boiling point of water in Celsius degrees?
100C
Energy and Matter
Convert 100C to degrees Fahrenheit.
Energy and Matter
Forces and MotionConvert 100C to degrees Fahrenheit.
F = (1.8 C) + 32
212 F = (1.8 100C) + 32
Drop of a Bullet
Convert 82 F to degrees Celsius.
C= (F – 32)
1.8
27.8 C = (82 – 32)
1.8
Energy and Matter
What is the freezing point of water in Celsius degrees if it is 32 in F?
Energy and Matter
What is the freezing point of water in Celsius degrees if it is 32 in F?
C= (F – 32)
1.8
0 C = (32 – 32)
1.8
Energy and Matter
Which form of thermal heat transfer does NOT require matter?
a.conduction
b.convection
c.radiation
Energy and Matter
Which form of thermal heat transfer does NOT require matter?
a.conduction
b.convection
c.radiation
Energy and Matter
To change into thermal energy, radiant heat must be __________ by matter.
a.absorbed
b.converted
c.diffracted
d.reflected
Energy and Matter
To change into thermal energy, radiant heat must be __________ by matter.
a.absorbed
b.converted
c.diffracted
d.reflected
Energy and Matter
What is the equation for calculating kinetic energy?
Energy and Matter
What is the equation for calculating kinetic energy?
KE = ½ mv2
But remember enter the numbers like
mv2
2
Kinetic energy is expressed in what units?
Energy and Matter
Energy is measured in what units?
Joules
Drop of a Bullet
Energy and Matter
What is the kinetic energy of a 5kg object traveling at 10m/s?
Energy and Matter
What is the kinetic energy of a 5kg object traveling at 10m/s?
KE = ½ mv2
KE = 5kg x (10m/s)2
2
= 250 J
Energy and Matter
What is the equation for calculating potential energy? What do the letters stand for?
Energy and Matter
Forces and MotionWhat is the equation for calculating
potential energy? What do the letters stand for?
PE = mgh
m = mass g = gravity (9.8m/s2)
h = height of the object in m
Drop of a Bullet
What is the gravitational potential energy of a 5 kg object 15 m above the ground?
Energy and Matter
What is the gravitational potential energy of a 5 kg object 15 m above the ground?
PE = mgh
PE = 5 kg x 9.8 m/s2 x 15 m
735 J
Energy and Matter
What is the equation used to calculate thermal energy change??
Drop of a Bullet
Energy and Matter
What is the equation used to calculate thermal energy change? What do the letters stand for?
Q = cmt
Q thermal energy change
c = specific heat m = mass
t = Final temp – initial temp
Energy and Matter
Copper has a specific heat of 385 J/(kg K). How much thermal energy would be needed to heat it from 300K to 325K? Assume a mass of 1 kg.
Energy and Matter
Copper has a specific heat of 385 J/(kg K). How much thermal energy would be needed to heat it from 300K to 325K?
Q = cmt
Q = 385 x 1 kg x (325 K – 300K)
9625 J / kg
assume one kg since mass isn’t given
Energy and Matter
If the temperature in a room is 23 degrees Celcius, what is the room temperature in degrees Fahrenheit?
Energy and Matter
If the temperature in a room is 23 degrees Celsius, what is the room temperature in degrees Fahrenheit?
F = (1.8 C) + 32
F = (1.8 x 23 C) + 32
= 73.4 F
Energy and Matter
