Physics 151: Computerized Recitation #13

Matter under Pressure


This recitation will focus on the ideal gas law and thermal stress -- both describe the behavior of matter under changing pressure. Please experiment with the Physlet simulations below and complete the required calculations on your worksheet.


Simulation 1: Thermal Expansion and Stress

Select Material:

Output Change in Length (m): Thermal Stress (N/m2):

The physlet above displays a rod that is 20 m in length at -100°C. The temperature is then raised to 100°C. The resulting change in length and the thermal stress assuming this change in length was prevented are then given. Note that thermal expansion may not be visible on the scale of our animation.

SubstanceCoefficient of Thermal Expansion aYoung's Modulus Y
Steel12 x 10-6 C°-120 x 1010 N/m2
Lead29 x 10-6 C°-11.6 x 1010 N/m2

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Simulation 2: Ideal Gas Law

Select Initial Bubble Radius Select Starting Bubble Depth

Output Initial Volume (m3): Output Final Volume (m3):Output Initial Pressure (N/m2): Output Temperature Ratio (:

A giant spherical air bubble rises in a large body of water as shown in the animation (position is in meters and time is in seconds) like what you might get from underwater industrial vents. You may control the original depth and size of the bubble. What does the ideal gas law say about how temperature changes between the initial depth and the surface?

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