temerature- measure of the average kinetic energy of all the particles in an object heat- thermal energy that flows from a warmer material to a cool material thermal energy- the sum of all the kinetic and potential energy of the particles in an object spacific heat- amoun tof thermal energy neede to raise the temperature of one kg. of a material 1C
Section Two
conduction- the transfer of thermal energy by collision between particles in matter convection- the tranfer of thermal energy in a fluid by movement of warmer and cooler fluid from place to place radiation- the trasnfer of energy by electronic waves insulator- a material in which heat flows slowly
Section Three
solar collectors- abosorb radiation enrgy form the sun thermodynamics- the study of the relationship between thermal energy, heat, and work first law of thermodynamics- increase of thermal energy of a sysytem equals the work done on the system plus the heat transfered to the system second law of thermodynamics- it is im possible for heat to flow through a cool object to a warmer object unless work is done
heat engine- a device that converst heat into work internal combustion engine- fuel is burned inside the engine in chambers of cylinders
Self Check
Self Check Section One
Explain: How energy moves when you touch a block of ice with your hand. Thermal energy from your hand will melt the ice.
Describe: How thermal energy of an object changes when the objects temperature changes. If the temperature goes up the thermal energy goes up or if the temperature goes down the thermal energy goes down.
Infer: When heat flows between two objects, does the temperature increase of one object always equals the temperature decrese of the other object? Explain. no because it depends on the specific heat of the object.
Explain: Why the specific heat of water is higher than the specific heat of most other substances. because other substances absorb more more thermal enrgy than water. Water would have to abosrb up to six times more thermal energy to keep up with other substances.
Think Critically: Explain wether or not the following statement is true. For any two objects the one with the higer temperature always has more thermal energy. yes it is true because the more heat o nobject has the more thermal energy it has.
Self Check Section Two
Explain: Why materials that are good conductors of heat are poor insulators. Because those materials are producing the heat and letting it go and the insulators are taking it in and keeping it.
Explain: Why the air temperature near the ceiling of a room tends to be warmer than near the floor. It is warmer because heat will raise.
Predict: Whether plastics foam, which contains pockets of air, would be a good conductor or good insulator. It would be a good insulator because it contains air pockets
Describe: How a convection current occurs. It is the transfer of thermal energy in a fluid by the movement of warmer and cooler fluid from place to place.
Think Critically: Several days after snowfall, the roofs of some homes on a street have almost no snow on them, while the roofs of other houses are still snow-covered. Describe what would cause this difference. One thing is that heat from the house could be makign the roof warm and melting the snow, or heat from other houses could be affecting the snow, or the houses could be close together and there wont be many trees so the sunlight could have a clear shot of the rooftop and melt the snow faster.
Section Three
Explain: How the thermal energy of a closed system changes with time. A forced-air system is a closed system the air will slowly get warmer if it is a heater.
Compare and Contrast: An active solar heating system with a radiator system. They both heat places. One heats by steam one heats by the suns rays.
Explain: Whether or not a heat engine could be made 100 percent effifient by eliminating friction. By burning gas and then the Air goes outside the engine
Diagram: How the thermal energy of the coolant changes as it flows in a refrigerator. Liquid coolent is pumped through an expansive valve.
Think Critically: Suppose you vigorously shake a bottle of fruit juice. Predict how the temperature of the juice will change. Explain your reasoning. I don't think the temperature will change, because it is not being heated by any forces.
Applying Math
section 1
6. Calucate the change in thermal energy of the water in a pond with a mass of 1,000 kg and a specific heat of 4,184 J/(kgC) if the water cools by 1C.
1,000kg X 1C X 4,184 J/(kgC)
4,184,000J.
7. Calucate the specific heat of a metal if 0.5 kg of the metal absorb 9,000 J of heat as it watms by 10C.
.5kg X 10C X 9,000 J/(kgC)
1,800C
section 2
6. Averaged over a year in the central United States, radiation from the sun trasfers about 200 W to each square meter of Earth's surface. If a house is 10 m long by 10 m wide, how much solar energy falls on the house each second?
10 X 10 X 200
20,000 W per second
section 3
6. Calculate change in thermal energy: You push down on the handle of a bicycle pump with a force of 20 N. The handle moves 0.3 m, and the pump does not absorb or release any heat. What is the change in thermal energy of the bicycle pump?
20 X .3
The change in thermal energy is 6
7. Calculate work: the thermal energy released when a gallon of gasoline is burned in a car's engine is 140 million J. If the engine is 25 % efficient, how much work does it do when one gallon of gasoline is burned?
140,000,000 X .25
35,000,000J
Vobaculary
Section One
temerature- measure of the average kinetic energy of all the particles in an object
heat- thermal energy that flows from a warmer material to a cool material
thermal energy- the sum of all the kinetic and potential energy of the particles in an object
spacific heat- amoun tof thermal energy neede to raise the temperature of one kg. of a material 1C
Section Two
conduction- the transfer of thermal energy by collision between particles in matter
convection- the tranfer of thermal energy in a fluid by movement of warmer and cooler fluid from place to place
radiation- the trasnfer of energy by electronic waves
insulator- a material in which heat flows slowly
Section Three
solar collectors- abosorb radiation enrgy form the sun
thermodynamics- the study of the relationship between thermal energy, heat, and work
first law of thermodynamics- increase of thermal energy of a sysytem equals the work done on the system plus the heat transfered to the system
second law of thermodynamics- it is im possible for heat to flow through a cool object to a warmer object unless work is done
heat engine- a device that converst heat into work
internal combustion engine- fuel is burned inside the engine in chambers of cylinders
Self Check
Self Check Section One
Self Check Section Two
- Explain: Why materials that are good conductors of heat are poor insulators. Because those materials are producing the heat and letting it go and the insulators are taking it in and keeping it.
- Explain: Why the air temperature near the ceiling of a room tends to be warmer than near the floor. It is warmer because heat will raise.
- Predict: Whether plastics foam, which contains pockets of air, would be a good conductor or good insulator. It would be a good insulator because it contains air pockets
- Describe: How a convection current occurs. It is the transfer of thermal energy in a fluid by the movement of warmer and cooler fluid from place to place.
Think Critically: Several days after snowfall, the roofs of some homes on a street have almost no snow on them, while the roofs of other houses are still snow-covered. Describe what would cause this difference. One thing is that heat from the house could be makign the roof warm and melting the snow, or heat from other houses could be affecting the snow, or the houses could be close together and there wont be many trees so the sunlight could have a clear shot of the rooftop and melt the snow faster.Section Three
Applying Math
section 1
6. Calucate the change in thermal energy of the water in a pond with a mass of 1,000 kg and a specific heat of 4,184 J/(kgC) if the water cools by 1C.
1,000kg X 1C X 4,184 J/(kgC)4,184,000J.
7. Calucate the specific heat of a metal if 0.5 kg of the metal absorb 9,000 J of heat as it watms by 10C.
.5kg X 10C X 9,000 J/(kgC)1,800C
section 2
6. Averaged over a year in the central United States, radiation from the sun trasfers about 200 W to each square meter of Earth's surface. If a house is 10 m long by 10 m wide, how much solar energy falls on the house each second?10 X 10 X 200
20,000 W per second
section 3
6. Calculate change in thermal energy: You push down on the handle of a bicycle pump with a force of 20 N. The handle moves 0.3 m, and the pump does not absorb or release any heat. What is the change in thermal energy of the bicycle pump?20 X .3
The change in thermal energy is 6
7. Calculate work: the thermal energy released when a gallon of gasoline is burned in a car's engine is 140 million J. If the engine is 25 % efficient, how much work does it do when one gallon of gasoline is burned?
140,000,000 X .25
35,000,000J