Teacher Demo: Air Pressure


This demo illustrates the presence of atmospheric air pressure and shows how the force that it exerts is greater than the force of gravity in some situations.

Procedure

Wear appropriate PPE: safety goggles.

  1. Fill the glass with water right up to the brim.
  2. Place the index card on top of glass and hold it firmly in place.
  3. Predict

Students engage in Think, Pair, Share (see Teaching Suggestions/Hints):

  • Think: What will happen when the glass is held upside down and the index card is no longer held in place?
  • Pair: Discuss the question with a partner.
  • Share: Hold a brief class discussion on the prediction.
  1. Explain

Ask students to justify their predictions using their existing knowledge.

  1. Observe

Lift the water-filled glass over the tray with one hand, holding the index card to the mouth of the glass with the other hand. Carefully turn the glass upside down. Release the card.

  1. Explain

Ask students to explain their observations.

Click here to download complete article….

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s