Intro

Worksheet

Beginner's Guide to Propulsion
Air Temperature
Activity

9" balloon

500 ml Erlenmeyer flask (or glass bottle with a mouth small enough for balloon to fit over)

boiling water

matches

laboratory burner

Before you begin: Remember to record observations of the balloon throughout the procedure.

 

Procedure:

1. Place water in the flask to cover the bottom (approximately two centimeters). Boil the water for three to four minutes. Wait one minute and pour the water out of the flask. Quickly place an uninflated balloon (just out of the package) around the mouth of the flask, sealing the flask. Let cool.
   
   
2. Compare the temperature of the gas molecules inside the flask with those outside the flask:
   A. before the flask was heated
   B. after the flask was heated
   C. after the balloon was placed on the flask
   
   
3. How does the change in temperature affect:
   A. the gas molecules' motion?
   B. the gas molecules' force?
   
   Note: To help with this question use the slide on Air Temperature in the Beginner's Guide to Propulsion.
   
   
4. Now click Engine Temperature Ratio (ETR) to note changes in air temperature.
   A. What happens to air temperature as air travels through the engine from stations 0 to 8?
   B. How does molecular motion change from stations 0 to 8?
   C. What is one function of a gas turbine engine?
   
   
5. The gas turbine engine displayed has a temperature variation of 3.5 from station 0 to station 8. If this engine were functioning at room temperature, what would be the temperature of the gas at station 8? Note: The temperature should be in Kelvin units. (K = 273 + Celsius)
   
   
6. What is the relationship between air temperature and molecular motion? How did you form this conclusion?
   
   
7. What is the relationship between air temperature and the force of the gas molecules? How did you form this conclusion?
   
   
8. After studying air temperature and gas turbine engines, list three questions that you or you and your lab partners now have about this topic.