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Trial 3 - Compare Air and Water

1. Your teacher will give you some warm and some cool tapwater, and a cup. Your task is to mix them until the water in your cup measures the same temperature as the air. Before you begin, make a prediction. Suppose the water and the air are the same temperature. If you tested the water with your finger, how would the water feel compared to the air? Choose one.

   a. The water would feel cooler.

   b. The water would feel warmer.

   c. The water and air would feel about the same temperature.

   Why do you think this would be true?

   
   
2. Now test your prediction. Connect the temperature sensor to the computer. Refer to Technical Hints to connect the temperature sensor. Measure the air temperature and record it. Refer to Technical Hints to record a single measurement.

   AIR TEMPERATURE =

   
   
3. Mix warm and cool water in your cup, stirring and measuring with the temperature sensor. Stop when the water temperature is within one degree of the air temperature. That's close enough!

   

   WATER TEMPERATURE =

   
   
4. Dip your finger into the water. How does water feel on you finger compared to air?

   

   a. The water feels cooler.

   b. The water feels warmer.

   c. The water and air feel about the same temperature.

   
   
5. Is there a difference between the feeling of temperature, and the measurement of temperature? Explain your answer. Think about what the water does to your finger, compared to what it does to the temperature sensor.