Background Research

BIG Picture

• The topic of this PBL is thermodynamics, a term that refers to the branch of physical science that deals with the relations between heat and other forms of energy (such as mechanical, electrical, or chemical energy), and, by extension, of the relationships between all forms of energy. In this case, I am referring to the transfer of heat between two objects. More specifically, an ice cube and an ice melting block.

Principles & Concepts

1. Fourier's Law states that the time rate of heat transfer through a material is proportional to the negative gradient in the temperature and to the area.¹

2. Newton's Law of Cooling states that the rate of change of the temperature of an object is proportional to the difference between its own temperature and the ambient temperature (i.e. the temperature of its surroundings).² Newton's Law of Cooling is represented by the following formula: T(t)=T_s+(T_o-T_s)e^-kt. T(t) represents the temperature at time (t). T_s represents the temperature of the surrounding environment. T_o represents the initial temperature of the object in question. K represents a constant.

3. The Law of Conservation of Energy (otherwise known as the first law of thermodynamics) states that energy cannot be created or destroyed in an isolated system.

4. The second law of thermodynamics states that the entropy of any isolated system always increases.

5. The third law of thermodynamics states that the entropy of a system approaches a constant value as the temperature approaches absolute zero.

¹ "Fourier's Law." Fourier's Law. University of Rochester, n.d. Web. 04 Oct. 2016.

² "Newton's Law of Cooling." Newton's Law of Cooling. University of British Columbia, n.d. Web. 04 Oct. 2016.

Key Words & Units of Measurement

1. Mass is the quantity of matter in a body regardless of its volume or of any forces acting on it.

2. The term thermal energy refers to "the internal energy of an object due to the kinetic energy of its atoms and/or molecules. The atoms and/or molecules of a hotter object have greater kinetic energy than those of a colder one." ³

3. Specific heat "the amount of heat per unit mass required to raise the temperature by one degree Celsius." ⁴

4. "Heat conduction (as opposed to electrical conduction) is the flow of internal energy from a region of higher temperature to one of lower temperature by the interaction of the adjacent particles (atoms, molecules, ions, electrons, etc.) in the intervening space."

5. "Heat capacity is the amount of heat required to raise the temperature of one mole or one gram of a substance by one degree Celsius without change of phase. Also, the ratio of the heat energy absorbed by a substance to its increase in temperature." ⁵

6. "Temperature is a measure of the tendency of an object to spontaneously give up energy to its surroundings. When two objects are in thermal contact, the one that tends to spontaneously lose energy is at the higher temperature." ⁶

7. Pressure is force per unit area.

8. Units of Measurement include: Celsuis, Fahrenheit, etc.

³ "Thermal Energy." Definition of Thermal Energy. Chegg, n.d. Web. 04 Oct. 2016.

⁴ Nave, R. "Specific Heat." Hyper Physics. Georgia State University, n.d. Web. 04 Oct. 2016.

⁵ "Definition of Heat Capacity." Dictionary.com. Dictionary.com, n.d. Web. 04 Oct. 2016.

⁶ Nave, R. "A More General View of Temperature." Hyper Physics. Georgia State University, n.d. Web. 04 Oct. 2016.

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