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Trial 2 - Air Pressure in a Juice Box

1. Measure the air pressure in the room. Refer to Technical Hints to connect the gas pressure sensor. Refer to Technical Hints to record a single measurement.
   
   
2. Without inhaling or exhaling with the straw, use your experimental setup to measure the air pressure inside the juice box.
   
   
3. Add your measurements to the drawing below. Refer to Technical Hints to use the drawing tool.
   
   
4. Is the air pressure in and outside the juice box the same?
   
   
5. Does it matter where outside the juice box you measure the air pressure?
   
   
6. Measure the air pressure in the juice box as you suck air out of the juice box. Show your results in the form of a graph. Refer to Technical Hints to record a series of measurements.
   
   
7. Label the graph when you started to inhale and when you stopped inhaling. Refer to Technical Hints to label a graph.

   
   

8. When the pressure inside the juice box is at its lowest point, what does the box look like? Make a drawing showing the box, the inside air pressure and the outside air pressure. Refer to Technical Hints to use the drawing tool.
   
   
9. What happens to the air pressure in the juice box when you stop inhaling?

   Nothing.

   It keeps going lower.

   It returns to the same as the outside air pressure.

   
   
10. Try exhaling into the straw. How does this affect the shape of the juice box?
    
    
11. What happens to the air pressure in the juice box when you stop exhaling?

    Nothing.

    It keeps going higher.

    It returns to the same as the outside air pressure.

    
    
12. On any given surface, air pressure exerts a force. This force acts like a push. Look at the cases below. If the wall is not sturdy, which way would you expect it to go?

    

    Case 1

    right

    left

    neither

    Case 2

    right

    left

    neither

    Case 3

    right

    left

    neither

    
    
13. Looking at the cases above, which case most closely matches the data you gathered in Trial 2 when you were sucking air out of the juice box?

    Case 1

    Case 2

    Case 3

    Explain.

    
    
14. Which case most closely resembles when you were neither sucking on nor blowing into the straw -- when you were just measuring the inside and outside air pressure?

    Case 1

    Case 2

    Case 3

    Explain.