Al Tobias (wat4y) - Office: Gibson S123 & Physics 218, (434) 924-0538
Demonstrations are cataloged according to PIRA Bibliography
PLEASE REQUEST DEMOS WELL IN ADVANCE
Due to Physics Building renovations, the lead time to set up demo requests has increased due to the need to transport equipment across campus. Please be kind and let me know well ahead of time what you need.
Choose a Topic or Enter a keyword to search:
|
You have selected the following Demos:
|
video - Thermocouple in IcePurpose:To demonstrate phase changes of water and the concept of latent heat.Procedure:      A thermocouple (TC) is frozen in a block of ice. The ice block is placed in a 1L glass beaker filled with ice cold water. The thermocouple is connected to a PASCO interface and a "Temperature vs. Time" graph is displayed on the projected computer screen in the classroom. Heat is applied until the ice melts. Its liquid phase (water) is further heated to its boiling point, releasing water vapor. On the plot, one can observe the frozen H2O ice temperature rise to 0C, then hold flat until all the ice is melted. This is due to the latent heat of fusion of H2O. With further heating, the temperature of the water rises to 100C. Then the temperature stays at 100C, because of the latent heat of vaporization for H2O.
Hints:!! This demo should be requested at least a day before it is needed. It takes time to prepare the ice block!! Using liquid nitrogen and glass Dewar, ice can be cooled down to -30 deg. Celsius. Typically takes about 25 minutes from start to finish.   |