US Department of Agriculture
Sink or Float?
Will it sink or will it float? Learners predict the outcome as they drop random objects into a container of water. Then, they keep track of the results and record the data in a t-chart to draw a final conclusion.
Teach Engineering
Determining Densities
Don't be dense—use a robust resource. The second installment of a five-part Floaters and Sinkers unit has learners determine the densities of several objects. As part of the activity, they learn the displacement method for finding...
DiscoverE
Design a Flotation Device
Save the soup! Scholars devise a flotation device using straws, balloons, foam, corks, and other objects. A can of soup must stay afloat for at least a minute with this device—your dinner might depend on it!
Museum of Science
Design a Submarine
Don't just sink the boat. Using a closed container as a submarine, pupils experiment to see what to add to the container to make it float, sink to the bottom, and hover in the middle. After finding one option, learners see if they can...
University of Waikato
Buoyancy in Water
Change where an object floats in water. Pupils experiment with a Cartesian diver by squeezing on the side of a plastic bottle. Learners pay attention to the bulb of the pipette as the bottle is squeezed to determine what is happening...
Teach Engineering
Clay Boats
Clay itself sinks, but clay boats float. Why? Young engineers build clay boats to learn about buoyancy. They test the weight the boats can hold using washers and then tweak their designs to make improvements, following the engineering...
PBS
Watercraft
Whatever floats your boat—with some additional weight. The first activity in a five-part series challenges pupils to design a boat to hold pennies. Using the design process, learners design, build, and test their boats, making sure they...
Center for Learning in Action
Properties of Balls
Enhance your states of matter lessons with a hands-on science investigation that compares six different balls' color, texture, size, weight, ability to bounce, and buoyancy.
Teach Engineering
Rock and Boat
Present the class with a question on whether the water level of a pond will rise they take a large rock out of a boat and drop it into the pond. Groups come down on all sides of the question and try to justify their answers. The activity...
DiscoverE
Water Sampling
What is the best way to test water quality? Using plastic bottles, scholars create monitoring sensors to test water quality. Creating three different sensors allows individuals to measure water quality at different water levels.
Teach Engineering
Buoyant Boats
Eureka! Using the clay boats made in the previous lesson, learners investigate the idea of buoyancy and water displacement to finish the last installment of five in a Floaters and Sinkers unit. Their observations during the activity...
Discovery Education
Motion in the Ocean
How do temperature changes affect ocean currents? Scholars explore convection currents by demonstrating the flow of water in a baking dish. They use ice, heat, and food coloring to see currents. Then, they draw conclusions about their...
American Chemical Society
Inquiry in Action: Changing the Density of an Object: Changing Shape
Throughout the activities in this investigation, students may have wondered how a boat made out of steel, which is more dense than water, can float. This activity addresses that question. Students will see that changing the shape of an...
American Chemical Society
Inquiry in Action: Changing the Density of an Object: Adding Material
In this activity, students see that a can of regular cola sinks while a can of diet cola floats. As a demonstration, bubble wrap is taped to the can of regular cola to make it float. This high-volume but light-weight material increases...
American Chemical Society
Inquiry in Action: Compare the Density of an Object to the Density of Water
In this activity, students use tea light candle holders and a student-made balance to compare the weight of equal volumes of wax, water, and clay. Students will discover that since the wax weighs less than an equal volume of water, it is...
Other
National Engineers Week Foundation: Flinker
Students investigate with common objects to see if they can make something that neither floats nor sinks, but rather "flinks" in the middle.
PBS
Pbs Learning Media: Buoyancy Brainteasers: Buoyancy Question
This interactive brainteaser from the NOVA: "Voyage of Doom" Web site challenges you to figure out what causes an object to sink.
TeachEngineering
Teach Engineering: Down With the Clip!
Students see how surface tension can enable light objects (paper clips, peppercorns) to float on an island of oil in water, and subsequently sink when the surface tension of the oil/water interface is reduced by the addition of a...
Center of Science and Industry
Cosi Columbus: Buoyant Bubble [Pdf]
Learn about density in this hands-on science experiment. Includes full list of materials, procedures, and scientific explanation of what makes an object float or sink. [PDF]
TeachEngineering
Teach Engineering: Clay Boats
Each student uses a small quantity of modeling clay to make a boat that will float in a tub of water. The object is to build a boat that will hold as much weight as possible without sinking. In the process of designing and testing their...