Egg Volume Relay

Objectives

• Measure the density of an egg using water displacement.

Materials

• Per Group of 4 students:
  1 egg (plus a few extra)
  1 pencil
  4 half-sheets of scrap paper
  a large graduated measuring cup (with graduated measurements on the glass) or a graduated cylinder wide enough to get an egg in and out
  a bucket or bowl to catch the possible water overflow

Key Questions

• Why does the rise in water level tell us the volume of the egg?
• Why was the goal to measure within 10 ml of each other? Why would the measurements not all be identical?
• Why do we write the second number above the first one rather than the other way around?

What To Do

Preparation

1. Set up 1 measuring station per group.
2. Each station should have one bucket/bowl containing a graduated measuring cup that has enough water to cover the egg completely, along with 1 pencil and 4 scrap sheets of paper.
3. Designate the “starting place” for each team. The stations and starting places should be arranged around the classroom, or outside if water spillage is a concern, in a way that the students from opposing teams will not bump into each other while running back and forth.

Game

1. Divide the students into teams of 4. Assign a station for each team.
2. Give each team 1 egg, 4 pencils and 4 sheets of paper.
3. This is a relay race. The first person will run with the egg to their measuring station, write down the water level, add their egg, write down the new water level, and subtract one from the other. This will give the amount of water displaced by your egg.
4. Once you have your answer, place the sheet of paper upside down next to your station.
5. Run back to your team and pass off the egg to the next team member.
6. The next team member takes the egg and repeats the same measurement drill.
7. Repeat the process 2 more times with the remaining teammates.
8. Each team has 4 members so each egg will get 4 measurements.
9. The winning team will be the fastest one that also has 4 measurements within 10 ml of each other (adjust the 10 mL allowance depending on the equipment and skill of your students).

Teacher Tip: If your students struggle with subtraction, help them out by printing this grid onto the sheets of paper

Extensions

• Introduce the term ‘displacement’. Displacement occurs when an object is immersed in a fluid, pushing it out of the way and taking its place. The volume of the fluid displaced can then be measured. The volume of the immersed object will be exactly equal to the volume of the displaced fluid.
• Find the volume of other objects in the classroom (for objects where water damage is not an issue).
• In SI (International System) units, density is equal to the mass in kg divided by the volume in cm3 or ml. As an extension for older students, you can have them calculate the egg’s density by dividing its mass (kg) by its volume (ml), as determined by this activity.