Thermal Expansion
PHYSICS FORM: 4D & 4E
TOPIC: THERMAL PHYSICS
Temperature determines the direction of net heat flow. It is the property o f an object. It’s the amount of kinetic energy a body possesses.
Example
Brass rod made hot at one end by placing it in a Bunsen flame, while other end is kept away at room temperature, there is a net transfer of energy from the high temperature region to the low temperature end.
THERMAL EXPANSION (See chp. 16 in Physics Text).
Three states of matter are solids liquids and gasses.
http://www.chem.purdue.edu/gchelp/liquids/character.html
Draw diagrams to show how the molecules are arranged in all three states below.
Experiments to illustrate expansion of solids, liquids and gasses. (page 103)
1. Expansion of Solids (fig. 16.7) • Bimetallic strip – consists of two different metals, usually brass ans steel (invar), riveted or welded together. The brass expands more than the steel, when the strip is heated. As a result the strip bends with brass on the other side of the curve.
http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/bimet.html
[pic] [pic]
• A ball and ring A metal ball fits through a hole in a ring. If the ball is heated it does not fit. http://www.youtube.com/watch?v=hX2Y2IDjuGI
2. Expansion of liquids (page 103, fig. 16.9a) A flask filled with coloured liquid and filled with a stopper carrying a long narrow tube. Flask is filled completely so that when stopper is in place it goes up the tube. When flask is heated level drops at first then rises. This drop is due to the expansion of glass container itself. One example is the liquid in glass thermometer (mercury laboratory thermometer.
3. Expansion of gasses (page 103, fig. 16.10b) By trapping a bead of coloured water in a narrow glass tube which goes through the stopper, and immersing the flask into a bath of hot water, one can demonstrate the
TOPIC: THERMAL PHYSICS
Temperature determines the direction of net heat flow. It is the property o f an object. It’s the amount of kinetic energy a body possesses.
Example
Brass rod made hot at one end by placing it in a Bunsen flame, while other end is kept away at room temperature, there is a net transfer of energy from the high temperature region to the low temperature end.
THERMAL EXPANSION (See chp. 16 in Physics Text).
Three states of matter are solids liquids and gasses.
http://www.chem.purdue.edu/gchelp/liquids/character.html
Draw diagrams to show how the molecules are arranged in all three states below.
Experiments to illustrate expansion of solids, liquids and gasses. (page 103)
1. Expansion of Solids (fig. 16.7) • Bimetallic strip – consists of two different metals, usually brass ans steel (invar), riveted or welded together. The brass expands more than the steel, when the strip is heated. As a result the strip bends with brass on the other side of the curve.
http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/bimet.html
[pic] [pic]
• A ball and ring A metal ball fits through a hole in a ring. If the ball is heated it does not fit. http://www.youtube.com/watch?v=hX2Y2IDjuGI
2. Expansion of liquids (page 103, fig. 16.9a) A flask filled with coloured liquid and filled with a stopper carrying a long narrow tube. Flask is filled completely so that when stopper is in place it goes up the tube. When flask is heated level drops at first then rises. This drop is due to the expansion of glass container itself. One example is the liquid in glass thermometer (mercury laboratory thermometer.
3. Expansion of gasses (page 103, fig. 16.10b) By trapping a bead of coloured water in a narrow glass tube which goes through the stopper, and immersing the flask into a bath of hot water, one can demonstrate the