Investigating Buoyancy: Calculating the Maxium Load of a Ship
Summary
Students will predict the maximum mass that a ship can hold without sinking. Students will then test their prediction by sailing their loaded ship.
CollapseLearning Goals
This activity is designed for students to demonstrate their ability to transfer the skill of calculating buoyancy into the action of accurately predicting the buoyant force on a loaded vessel. Students will use critical thinking skills to calculate the volume of an irregularly-shaped ship and successfully demonstrate their knowledge of forces by incorporating all of the parts of the buoyant system into the solution.
Key terms: Buoyant force, Archimedes' Principle
Key terms: Buoyant force, Archimedes' Principle
Context for Use
This is a lab-based activity designed for ninth grade physical science. Students will have been introduced to Archimedes' Principle and expected to know how to calculate buoyant force.
Modification 1: This could be used as an introduction to buoyancy by allowing students to discover that the mass of the load put into the ship always equals the mass of the water displaced by the floating ship.
Modification 2: This activity could be made more challenging by exchanging another displacement liquid in place of the water.
Time: Two 45-minute class periods.
Materials: Bread loaf pans (ship), sand, ruler, balance, large clear plastic container (for sailing the ships), and access to water.
Modification 1: This could be used as an introduction to buoyancy by allowing students to discover that the mass of the load put into the ship always equals the mass of the water displaced by the floating ship.
Modification 2: This activity could be made more challenging by exchanging another displacement liquid in place of the water.
Time: Two 45-minute class periods.
Materials: Bread loaf pans (ship), sand, ruler, balance, large clear plastic container (for sailing the ships), and access to water.
Description and Teaching Materials
1. Student teams of 3-4 individuals will be given a bread-loaf pan (ship) and asked to predict the maximum load of sand (in grams) their ship can hold.
2.As an incentive to push the limits of the ship's ability to carry a load, the teams will be competing for who can load their ship with the most sand and still stay afloat.
3. Teams will measure the volume of their ship and convert this data into the mass in grams of sand their ship can hold. (Buoyant force equals the mass of water displaced by the ship.)
4.Teams will not be allowed to test their ship in the water prior to the competition.
5. Each team will load their ship, once it is in the water, with sand that has been massed by the team and put into a container, ready for loading.
2.As an incentive to push the limits of the ship's ability to carry a load, the teams will be competing for who can load their ship with the most sand and still stay afloat.
3. Teams will measure the volume of their ship and convert this data into the mass in grams of sand their ship can hold. (Buoyant force equals the mass of water displaced by the ship.)
4.Teams will not be allowed to test their ship in the water prior to the competition.
5. Each team will load their ship, once it is in the water, with sand that has been massed by the team and put into a container, ready for loading.
Teaching Notes and Tips
It is important that teams are not allowed to place ships into the water prior to the test. The most overlooked part of the problem is failure to include the mass of the ship as part of the load. Teams that successfully include the ship's mass demonstrate a good synthesis of thought in how they approach problem-solving.
Assessment
A final lab report from each team including measurement data, force calculations, experiment conclusions, and descriptions and thoughts on improvement will be submitted to the instructor following the activity.
Standards
II. Physical Science (9-12)
D. The student will understand the nature of force and motion.
E. The student will understand the forces of nature and their application.
D. The student will understand the nature of force and motion.
E. The student will understand the forces of nature and their application.