In this lesson, the students will discover the relationship between an object's mass and the amount of space it takes up (its volume). The students will also learn about the concepts of displacement and density.
This activity is a lab project where students observe what happens when you try to mix oil and water. It can also be used to work with density.
The purpose of this resource is to measure the bulk density of each horizon in a soil profile. In the field, students collect three soil samples from each horizon in a soil profile using a container with a measured volume. In the classroom, students weigh the samples, dry them, and weigh them again to determine their dry mass and water content. Students then sieve the dry soil samples and measure the mass and volume of any rocks and material with dimensions greater than 2 mm. Students use the Bulk Density Data Sheet to calculate the soil bulk density for each sample.
When will objects float and when will they sink? Learn how buoyancy works with blocks. Arrows show the applied forces, and you can modify the properties of the blocks and the fluid.
Students will conduct a simple experiment to see how the water level changes in a beaker when a lump of clay sinks in the water and when the same lump of clay is shaped into a bowl that floats in the water. They will notice that the floating clay displaces more water than the sinking clay does, a result that will probably surprise them. They will then determine the mass of water that is displaced when the clay floats in the water. A comparison of this mass to the mass of the clay itself should reveal that they are approximately the same.
This activity has students create a Cartesian diver, which will act in some ways like a submarine. Students will adjust the amount of air and water in an inverted test tube (the "diver") so that it at first barely floats in a water-filled bottle. Then, they will squeeze the closed bottle to create higher water pressure, causing the diver to sink. Releasing the bottle allows the diver to float again. Written instructions, a list of materials, and illustrations are included.
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 boats, students discover some of the basic principles of boat design and gain first-hand experience with concepts such as buoyancy and density.
Why do objects like wood float in water? Does it depend on size? Create a custom object to explore the effects of mass and volume on density. Can you discover the relationship? Use the scale to measure the mass of an object, then hold the object under water to measure its volume. Can you identify all the mystery objects?
Students explore the densities and viscosities of fluids as they create a colorful 'rainbow' using household liquids. While letting the fluids in the rainbow settle, students conduct 'The Great Viscosity Race,' another short experiment that illustrates the difference between viscosity and density. Later, students record the density rainbow with sketches and/or photography.
In this video segment adapted from ZOOM, the cast discovers that gas-filled bubbles act like life jackets for raisins, making them buoyant.
Why does an egg float in salt water? Learn about density and buoyancy in this video segment adapted from ZOOM.
Watch warm water float on top of cold water in this video segment adapted from ZOOM.
This video segment adapted from ZOOM offers a clever demonstration of buoyancy by showing how to pour a cup of air into a cup filled with water.
Will a grape float in oil? Will a metal nut sink in corn syrup? Watch as the ZOOM cast tests the buoyancy of a variety of liquids and objects.
Students will use two different methods to determine the densities of a variety of materials and objects. The first method involves direct measurement of the volumes of objects that have simple geometric shapes, while the second uses the water displacement method to determine the volumes of irregularly-shaped objects. After the densities are determined, students will create x-y scatter graphs of mass versus volume, and these graphs will reveal that objects with densities less than water (floaters) lie above the graph's diagonal, and those with densities greater than water (sinkers) lie below the diagonal.
Exercises on Systems and Density.
Design Challenge created to teach students about buoyancy, density, volume and pressure.
This inquiry-based learning activity allows students to explore the relationships between mass, volume, density, and buoyancy as they manipulate various materials to construct a submersible "vehicle" for deep-sea research.
Design and build a vessel with its own propulsion system that will carry cargo across a wading pool. PDF document.
This curricular unit introduces students to the important concept of density. The focus is on the more easily understood densities of solids, but students can also explore the densities of liquids and gases. Students devise methods to determine the densities of solid objects, including the method of water displacement to determine volumes of irregularly-shaped objects. By comparing densities of various solids to the density of water, and by considering the behavior of different solids when placed in water, students conclude that ordinarily, objects with densities greater than water will sink, while those with densities less than water will float. Students then explore the principle of buoyancy, and through further experimentation arrive at Archimedes' principle, which states that a floating object displaces a mass of water equal to its own mass. They may also be surprised to discover that a floating object displaces more water than a sinking object of the same volume.
