# Difference between revisions of "Density Lab"

Density Lab

Type Physics
Category Lab

Density Lab, also known by the names Buoyancy Lab and Buoy Oh Buoy, is a new event rotating in for the 2019 season. It was previously a trial event at the 2018 National Tournament. This events consists of two parts - a written test on density, buoyancy, concentrations, and the behavior of gases, and one or more hands-on tasks relating to those concepts (in this way, the event is structured similarly to another Physics event, Shock Value/Circuit Lab).

## Test Description

A Density Lab test will normally require the basic or previous knowledge of chemistry and in some cases simple physics. An event like Chemistry Lab can really help you excel during the test if you understand the concepts.

Students may be required to:

• measure or calculate the mass density of a given solid
• collect a volume of gas and calculate the volume, mass, and mass density
• determine the number density of multiple objects, such as a bag of brown M&M's
• determine the mass that a given helium balloon can lift
• determine the depth to which an object may sink in water
• determine the density of a material at different temperatures

## What is Density?

Basic Density Equation.

Density: the degree of compactness of a substance. As shown by the image to the right, is the basic density equation. This equation will be crucial for solving many of the basic density questions in Density Lab.

### Gas Laws

Gas Laws are needed so that an understanding of gases behavior and how they pressurize. Most tests will require an understanding of gas behavior.

Most basic gas law equations.

### Archimedes' Principle

Example of Archimedes' Principle

Archimedes' Principle will be one of the most important concepts to learn for this event.Archimedes' Principle:any body completely or partially submerged in a fluid (gas or liquid) at rest is acted upon by an upward, or buoyant, force the magnitude of which is equal to the weight of the fluid displaced by the body. The volume of displaced fluid is equivalent to the volume of an object fully immersed in a fluid or to that fraction of the volume below the surface for an object partially submerged in a liquid. The weight of the displaced portion of the fluid is equivalent to the magnitude of the buoyant force. The buoyant force on a body floating in a liquid or gas is also equivalent in magnitude to the weight of the floating object and is opposite in direction; the object neither rises nor sinks.