Bag of Balls

Summary

Students in small groups will determine the density of various balls and predict their ability to float or sink.

Materials

• Zip lock bags with 5-7 Balls. (nerf, ping pong, super, wood, Styrofoam, marble, wiffle)
• Calculators
• Overflow cans and measure the water for the volume. A small beaker full of water in a large beaker will also work for the Overflow cans.
• Graduated Cylindar
• Metric rulers and string if you want to use the diameter for the volume formula
• Triple beams
• Aquarium 3/4 full of water to test the balls in after.
• (you could use overflow cans and measure the water for the volume)
• Student worksheet

Student Prior Knowledge

mass, volume, density, formula for a sphere volume, density of water.

Instructional Procedures

Special teacher procedures, safety notes, and suggestions:

• In teams of 2-4 predict if the balls will float or sink in water.
• Discuss how to measure the volume of a sphere. It can be done with an overflow can and measuring the water or with a string to measure the diameter
• If they use the diameter use this formula. (use the TI73 calculator) # for diameter y to the xth key 3 X 0.5
• Have them now figure out the mass and volume of the balls then the density.
• After all students are done the teacher will put the balls one at a time in the water to determine if they will float or sink.
• Discuss the reasons. Make sure that they are understanding density.

Assessment Plan

Check for completeness and correct answers.

Bibliography

Lesson Design by Jordan School District Teachers and Staff.