Flotation Exploration
Science Standards Addressed (from the Colorado Department of Education)
Standard 1 - Physical Science
• 6th Grade: Outcome 4: Distinguish among, explain, and apply the relationships among mass, weight, volume, and
density. (DOK 1-2)
• Kindergarten: Outcome 2: Objects can be sorted by physical properties, which can be observed and measured.
(DOK 1-2)
• Preschool: Outcome 1: Objects have properties and characteristics. (DOK 1-2)
Math Standards Addressed (from the Colorado Department of Education)
Standard 4 - Shape, Dimension, and Geometric Relationships
• 4th Grade: Outcome 1: Appropriate measurement tools, units, and systems are used to measure different
attributes of objects and time. (CCSS: 4.MD.1)
• 3rd Grade: Outcome 3: Time and attributes of objects can be measured with appropriate tools. (CCSS: 3.MD.1)
• 2nd Grade: Outcome 2: Some attributes of objects are measurable and can be quantified using different tools.
• 1st Grade: Outcome 2: Measurement is used to compare and order objects and events.
• Kindergarten: Outcome 2: Measurement is used to compare and order objects. (CCSS: K.MD.1, K.MD.2)
• Preschool: Outcome 1: Shapes can be observed in the world and described in relation to one another.
Objective:
Students should learn what determines whether objects float and be able to predict
whether objects will float or sink.
Materials:
Clear tub full of water (must be tall enough to allow largest bottle to sink)
Two sets of at least two bottles (i.e. two smaller bottles and two larger bottles)
Marbles that can fit into the bottles
Balance (low-precision scale will work as well, and would be better for advanced grades)
Procedure:
1. Help students compile list of objects that sink and list of objects that float
2. Lead discussion among students to hypothesize what makes the two lists different
3. Bring out small empty bottle and predict whether it will sink or float
4. Demonstrate that the empty bottle floats
5. Predict what will happen as marbles are added to the bottle and test
6. After enough marbles are added to sink the bottle, stop for discussion
7. Collect ideas about what was important about the amount of marbles added
8. Fill identical bottle with water and compare it to the sinking bottle (flotation, size, weight)
9. Discuss the relative weights in the two similarly sized bottles, effects on flotation
10. Introduce larger bottle
11. Explore how we can put the most marbles in the bottle without allowing it to sink
• Depending on grade, relate this to engineering problems where modeling is necessary (e.g. building a
boat and knowing how much it can carry safely)
• Guide the students toward finding the following solution
12. Fill identical bottle with water and add marbles to original bottle until it is just lighter than the water-filled bottle
13. Demonstrate that the bottle weighing just less than [the water it displaces] the water filling the same-size bottle
14. Add one more marble and demonstrate that the bottle sinks
15. Introduce the word density and the quantities it relates (mass/volume)
Optional extension:
16. Encourage students to predict what will happen if we indent/crush a bottle that barely floats
17. Demonstrate that reducing the volume increases the density
• Density is mass/volume, reducing denominator increases value
Prepared by Brian Vogler
Developed with Cassie Olson
Updated 11/18/2013
Created 10/23/2013