Unit 3: Density and Buoyancy

Marion, Brandin, Marion, Jessica

To the left is the device in which buoyancy is calculated, and to the right is a scale in which mass is calculated.

Within this unit we learned how to calculate density, mass, and buoyancy.  There are three different equations for density: density=mass/volume, mass=density * volume, volume=mass/density.  To find the mass of an object you can also put an object on a scale to find the weight.  Volume can be found in three different ways: (l)(w)(h), water displacement, and graduated cylinder.  To find the buoyancy of an object you find the water displacement of the object.

8th Grade Science Standards Covered:

All objects experience a buoyant force when immersed in a fluid. As a basis for understanding this concept:

1. Students know density is mass per unit volume.
2. Students know how to calculate the density of substances (regular and irregular solids and liquids) from measurements of mass and volume.
3. Students know the buoyant force on an object in a fluid is an upward force equal to the weight of the fluid the object has displaced.
4. Students know how to predict whether an object will float or sink.