Vernier Software and Technology
Vernier Software & Technology


Figure from experiment 4 from STEM 2 with Vernier and LEGO® MINDSTORMS® NXT


Buoyancy is the upward force exerted by a fluid on an object. The buoyant force on the object reduces the weight of the object. When an object is immersed in water, it pushes water aside. Over 2000 years ago, the Greek mathematician Archimedes discovered that the buoyant force is equal to the weight of the water displaced (pushed aside) by the object. Buoyancy is used to determine whether an object will sink or float. If the object weighs more than the water it displaces, it will sink; if it weighs less, it will float. Engineers use the principle of buoyancy when designing boats, submarines, and scuba equipment. In this activity, you will use a Force Sensor to determine the buoyant force and the weight of displaced water for three different objects.


In this experiment, you will

  • Use a Force Sensor and NXT to measure the weights of objects in and out of water.
  • Determine the buoyant force of water on each object.
  • Determine the weight of water displaced by each object.
  • Compare buoyant force to weight of water displaced for each object.
  • Use the results of the experiment to explain why objects sink or float.

Sensors and Equipment

This project/activity features the following Vernier sensors and equipment.

Additional Requirements

You will also need NXT Sensor Adapter and a LEGO MINDSTORMS NXT robotics system.

STEM 2 with Vernier and LEGO® MINDSTORMS® NXT

See other experiments from the lab book.

2First-Class Levers
3Audio Assistant
6String Tension Tester
7Gas Pressure
8Yeast in Action
9Grip Strength
10Cartesian Diver
12Lemon Battery
13Battery Tester
14Solar Cells
15Solar Tracker
16Mapping a Magnetic Field
18Migrating Robot
19Magnet Finder
20Mine Sweeper

Project/activity 4 from STEM 2 with Vernier and LEGO® MINDSTORMS® NXT Lab Book

<em>STEM 2 with Vernier and LEGO<sup>®</sup> MINDSTORMS<sup>®</sup> NXT</em> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

Buy the Book

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