Thermal Physics

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Thermal Physics

Thermal energy, E_Therm : the kinetic energy of the particles (movement) and the energy related to the bonds between the molecules (called potential energy) that changes, when there is a change in phase.

Chemical energy, E_Chem : The energy of the bonds between the atoms in the molecules.

Nuclear energy, E_Nuc : The energy of the nucleus of the atoms.

Internal energy: The sum of the thermal, chemical and nuclear energy.

1. Look at the picture below. If half of the particles of the gas were removed from the container (and nothing else was changed), how would the following properties of the gas change?

a. Density?_________________________________________________________________

b. Pressure?________________________________________________________________

c. Temperature?_____________________________________________________________

2. A can contains 50cm³ of air at a pressure of 120 kPa. What will its volume be if the pressure on it is increased to 400 kPa?

3. Two buckets contain water at 30°C . One contains 1kg of water, the other contains 2kg of water. State and explain whether the following quantities are the same or different for the water in the two buckets:

a. Internal energy

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b. Temperature

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c. Average energy of a molecule

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4. Name the three types of heat transfer.

a. ______________________

b. ______________________

c. ______________________

5. Label the heat transfer process for each of the following pictures.

6. In cold climates, it is important to keep a house well insulated. Listed below are three ways of insulating a house. For each, explain how it reduces heat loss. In your answers, refer to the three different types of heat transfer.

a. Heavy curtains, when closed, trap air next to the window.

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b. Shiny metal foil is fitted in the loft, covering the inside of the roof.

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c. Glass wool is used to fill the gap in the cavity walls.

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