Trapped Inside - Student Activity

Materials

• Inflated soccer ball at standard playing pressure (this should be printed on the outside of the ball)
• Air pump
• Pump needle
• Balance
• Mason jar lid
• Ruler

Procedure

1. Collect all materials from the list.
2. Measure the mass of the jar lid, and record the mass on your data sheet.
3. Place the jar lid on the balance to hold the soccer ball in place while you are measuring its mass.
4. Measure the mass of the inflated soccer ball and the lid. Record the mass on your data sheet.
5. Measure the width of the ball. This is called the diameter. One half of the diameter is the radius. Record your measurement of the radius (in cm) on the data sheet.
6. Place the needle in the soccer ball and allow air to escape from the ball. Do not squeeze the ball; wait until the air has stopped coming out on its own. This means the ball should now be at a pressure close the normal air pressure in the room.
7. Weigh the ball and lid and record the mass on your data sheet. Find the mass of the air that escaped.
8. Complete the calculations and questions on the Data Sheet.