Background:

Heat and mechanical energy are different types of energy that can be converted from one to another. Joule's famous experiment demonstrated this in an innovative way, by using falling masses that turned the paddles which heated up water in a container:

An increase in the masses means more potential energy, and a greater increase in temperature of the water when the masses fall. But is the same transfer of energy evident in a solid?

By using a simple jar of sand, you can test if it is possible to use the kinetic energy of motion to heat a solid.

The Question:

Is it possible to convert kinetic energy into heat?

Variables:

Identify the type of data you will collect to support your hypothesis and state the manipulated, responding and controlled variables in this investigation.

Materials:

• temperature sensor
• computer interface, such as a USB link
• dry sand
• jar with lid

Procedure:

Step 1:

Step 2:

Configure your data collection software to display a temperature vs time graph.

Step 3:

Fill the glass jar about two-thirds full with dry beach sand. Place the temperature sensor into the sand in the jar. Start recording data and watch the graph for about 10 seconds. Stop recording data.

Step 4:

Take the temperature sensor out of the sand and put the lid on the jar. Shake the jar vigorously for 5 or 6 minutes. You may want to take turns shaking.

Step 5:

Open the jar and place the Temperature Sensor down into the sand again. Start recording data and watch the graph for about 10 seconds. Continue recording for another 2 minutes, and then stop recording data.

Step 6:

When you have finished collecting your temperature data, you are ready to analyze it. To do this, click the graph to make it active. Re-scale the graph by clicking the Scale to Fit button (top left hand corner of the graph display).

Analyzing and Interpreting:

1.	Label the lines on the graph - the labels should indicate before and after shaking of the jar.
2.	What was the effect of shaking on the temperature of the sand? What type of energy transformation(s) occurred?
3.	In step 5, you allowed the computer to collect data for two minutes. Observe the shape of the line and explain any change in the temperature of the sand during the 2 minute period.
4.	Offer an explanation of how the heating of the sand occurred due to shaking.

Forming Conclusions:

Based on the data you have collected, write a summary statement for the following question:

5.	Is it possible to convert kinetic energy into heat?