Air Pressure - Newspaper

INTRODUCTION

Air is all around us and it exerts pressure in all directions. This experiment will show the exertion of air pressure on the newspaper.

MATERIALS

• Sheet of newspaper
• Ruler

WHAT TO DO

1. Spread the newspaper smoothly across a table. If the newspaper was folded, make sure the inside of the paper is facing up and the outside is facing the table (otherwise air gets underneath and the results are not what they need to be).
2. Place the ruler partway underneath the paper, with one end of the ruler extending beyond the edge of the table a few inches.
3. Bring your hand down on the end of the ruler extended beyond the table edge (you can push as hard as you like!)

QUESTIONS

1. Why doesn't the paper go flying into the air?

SUMMARY

The pressure applied to the newspaper by the ruler by the experimenter's hand is less than the pressure applied by the air. In other words, the air is pushing down on the newspaper more than the ruler is pushing up on it. Therefore, the air pressure is holding the newspaper to the table. The force needed to lift the newspaper into the air is too large to produce with the ruler.

SOURCE

NASA Website: http://ldaps.ivv.nasa.gov/curriculum/curriculum/airpressure2.html

© S. Olesik, WOW Project, Ohio State University, 1999.