2/26/15 - Heat Energy Transfer Continued

Heating up the metal ring for our first visual representation of thermal expansion. The heat makes the ring expand in all directions.

Our predictions to what will happen to metal as it heats up, we made a model for a solid chunk and the metal ring from the previous picture.

We listed factors that we think would directly or inversely affect thermal expansion.

A bimetal strip of invar and brass, brass is affected more by the heat and expanded more for the heat applied to the strip. The difference in thermal expansion caused the strip the bend toward one side.

Our predictions to what would happen if heat was applied to the bimetal strip; we concluded that if heat was added, then the brass side would see a larger change in length due to thermal expansion.

Before and after of the same metal strip with heat being applied to it, again the brass side changes more due to the higher expansion.

The metal strip now bends the other way due to being submerged in water, thermal expansion works both ways to contract and expand.

Since brass has a higher coefficient to expand or contract, the strip bends accordingly.

 What we had predicted would happen from thermal expansion of the strip.

A setup for the linear expansion of a aluminum rod, steam will be applied to the aluminum rod and the distance changed will be recorded by the rotary sensor connected to LoggerPro.

Closeup of the rod resting on the rotary sensor.

Symbolic calculation for the linear expansion of the aluminum rod. 

The experiment running, steam is being sent through the pipe and it's heating up to 100 degrees Celsius.

A picture of the device that emits the steam used to heat up the pipe.

A small mass was added to the end of the rod to prevent it from slipping on the rotary sensor.

Our given values from which we will use to solve for the thermal expansion of the rod.

A graph of the data recorded using the sensors and LoggerPro.

We calculate for the expansion constant of aluminum.

Here is a separate calculation for uncertainty of the expansion constant. We found that taking all factors into account, the result would be allowing our answer to fall within range of the accepted value.

Factors taken into account are that the rod was not measured, just assumed, along with the radius of the rotary sensor, un-calibrated thermal sensor and rotary sensor.

An induction heater is added to an unknown amount of water and ice.

While the heater is running, someone is constantly stirring with the the thermal sensor. 

The graph of the temperature reading over a course of 400 seconds. There is a clear linear rate for most of the process, and exponential for the ends of the graph.

Our predicted graph of the experiment and given the dQ of the heater and slope of the temperature change, we calculate for how much water and ice was in the cup prior to heating.

When the water hit boiling point, we started to lose some to vaporization. This is the calculation for vaporization of the water, we found an answer for how much of the water was lost due to the heat transfer after boiling point.

Additional practice problems of having a block of ice and adding heat to said block.

Additional practice of finding the mass of water that it would take to bring a solution to equilibrium at a specific temperature.

Calculations for the pressure difference when we blew into one end of the tube. I don't have the video for this part due to failure to communicate for the video from a classmate.