WORKSHEET 4

Activity - Bottled Up Tornadoes

Print and copy this worksheet for use in the classroom.

 
 
In this activity you will make your own tornado in a bottle.
Bottles Diagram

Equipment

  • two 2 litre PET bottles with the labels removed
  • water (you might like to add some coloring)
  • paper towel
  • flat, metal washer with the same circumference as the mouth of the bottles
  • duct tape (alternatively, buy a ready made plastic bottle neck joiner, which can be purchased at Australian Geographic Shops at minimal cost)
 

Safety

PET bottles used by younger children should have their plastic rings removed
 

Procedure

  1. Make sure that the plastic rings are removed from the necks of the bottles.
  2. Half fill one bottle with water.
  3. Dry the opening of the bottle with paper towel then place the washer over it.
  4. Place the second bottle upside down on top of the washer.
  5. Carefully secure the bottles together with tape.
  6. Turn the bottles upside down so that the bottle containing the water is on top.
  7. Observe what happens.
  8. Now hold the lower bottle with one hand and the upper bottle with the other hand.
  9. Support the lower bottle while quickly moving the top of the upper bottle in a clockwise direction.
  10. Stand the bottles upright, with the empty bottle remaining underneath.

 

Questions

Answer the following questions in the spaces provided.

 

 
  1. What did you expect to observe when the bottle containing water was placed above the empty bottle?







  2. What did you observe after you moved the top bottle in a circle?








  3. Why do you think that spinning the top bottle made a difference to how quickly the water flowed ?







  4. What atmospheric event are tornadoes commonly associated with ?

 


Explanation

  The water inside the upper bottle swirls, forming a funnel shape as it pours into the lower bottle. You have probably seen this happen when you let water out of a bath. The funnel formed by the swirling water is called a vortex (a whirling mass of air or water). The vortex formed in the water is the same shape as the vortex formed by a tornado (a violently rotating funnel cloud that touches the ground). Tornado formation appears to be related to the convergence (meeting) of air occurring underneath a developing cumulonimbus cloud. The swirling air is then tilted upwards to form the tornado. Air flows into the tornado through the bottom and out through the top. Tornadoes are also called twisters. They range in size from a few metres across to about a kilometre wide.
 


Extension Activity

  Investigate whether the direction of spinning affects the rate at which water flows from the top bottle to the bottom one. Does the water move more quickly if the top of the bottle is spun quickly?
 


Fact File

 

During the 1960's, a thunderstorm and a rapidly moving cold front produced a tornado in Sydney. It was about 600 metres high and 50 metres wide. As it passed through Cremorne, wind speeds reached 210 kilometres per hour. In little over a minute, a million dollars' worth of damage had been done. The tornado uprooted trees, lifting them into the air. It also destroyed roofs and caused windows to explode and car boots to fly open.

More tornadoes form on the flat plains east of the Rocky mountains in the United States than anywhere else on earth.

This activity is courtesy of
the Cooperative Research Centre for Southern Hemisphere Meteorology