How to Make a Barometer

Science Exhibition Models

Things you will need:

  • Permanent Marker
  • Solid paper- Card like
  • Straw
  • Transparent Tape
  • Rubber Band
  • Jar
  • Scissors
  • Balloon

How to do it:

  • Take the balloon and cut its top off.
  • Take and rubber band and use it to fix the cut balloon over the jar by stretching it out.
  • The straw will be fixed over the balloon (use the tape) and in such a manner that one third of it hangs over the edge.
  • Use a scale and draw three lines over the card at an equal space of half centimeter. These lines will be labeled as low, moderate and high.
  • The card should be taped to the backside of the jar making the straw point towards moderate.
  • Place this apparatus somewhere indoors on a flat surface.

What’s going on?

In a low-pressure situation the balloon will swell up and the straw will start pointing downwards. This happens due to the air pressure difference as the air inside has higher pressure than outside and thus it expands the balloon out.

Similarly in a high-pressure environment the external air will push the balloon inside and the straw will point upwards. This happens as the air in the balloon has low pressure. In a general sense low pressure results in bad weather whereas high pressure results in good weather. You can create a full weather report with combining several factors such as the winds direction and speed and rainfall.


Practise This Question

In which one of the following cases will the liquid flow in a pipe be most streamlined