Everything that we've covered in this course so far has been applied to solid objects (specifically rigid objects that do not deform or change shape).

But many of the physical laws, concepts and equations that we've learned also apply to fluids.

A fluid is a material that has no fixed shape and will continue deforming if any force is applied to it. The category of fluids includes liquids (like water) and gasses (like the atmosphereic air around us) and we're going to learn about both. The main difference between the two is that liquids are (nearly) incompressible and do not change volume when compressed, but gasses are very compressible. In this lesson we'll learn about ideal fluids which are incompressible and have no viscosity (they flow more like water than honey).

We're going to learn about density, which is how much mass a fluid has per unit of volume. This is what determines whether an object will sink or float in water (or any fluid). Density is a simple concept but we're going to use it a lot in the next few lessons.

Multiple-Choice Questions

Answers

• Characteristics of a Fluid
• States of Matter
• What Is Density?
• Density

• Organic Chemistry Tutor - Density Problems
• Density Practice Problems
• Advanced Density Problem
• Density problem examples

• TED-Ed - Why does ice float in water?
• Efficient Engineer - Understanding Fluids and Viscosity
• Hyperphysics - Fluids

• Volume conversion tool

Other Resources

Everything that we've covered in this course so far has been applied to solid objects (specifically rigid objects that do not deform or change shape).

But many of the physical laws, concepts and equations that we've learned also apply to fluids.

A fluid is a material that has no fixed shape and will continue deforming if any force is applied to it. The category of fluids includes liquids (like water) and gasses (like the atmosphereic air around us) and we're going to learn about both. The main difference between the two is that liquids are (nearly) incompressible and do not change volume when compressed, but gasses are very compressible. In this lesson we'll learn about ideal fluids which are incompressible and have no viscosity (they flow more like water than honey).

We're going to learn about density, which is how much mass a fluid has per unit of volume. This is what determines whether an object will sink or float in water (or any fluid). Density is a simple concept but we're going to use it a lot in the next few lessons.