Barometer: Explanation and Study Guide

What is a Barometer?

A barometer is a scientific instrument used to measure atmospheric pressure. Atmospheric pressure, also known as barometric pressure, is the force per unit area exerted by the weight of the air above a given point in the Earth's atmosphere.

Types of Barometers

There are several types of barometers, but the two most common types are:

Mercury Barometer: This type of barometer uses a column of mercury to measure atmospheric pressure. As the atmospheric pressure changes, it causes the level of mercury in the column to rise or fall.
Aneroid Barometer: An aneroid barometer uses a small, flexible metal box called an aneroid cell. As the atmospheric pressure changes, the cell expands or contracts, which is then translated into a pressure reading on a dial.

How a Barometer Works

Barometers work on the principle that changes in atmospheric pressure will cause a corresponding change in the height of the column of liquid (in the case of a mercury barometer) or the movement of the aneroid cell (in the case of an aneroid barometer).

Uses of Barometers

Barometers are used for various purposes, including:

Weather forecasting: Changes in atmospheric pressure can indicate the approach of weather systems, such as storms or clear skies.
Aviation and marine navigation: Pilots and sailors use barometric pressure readings to determine altitude and make navigational decisions.
Scientific research: Barometric pressure measurements are used in meteorology, climatology, and other scientific fields.

Studying Barometers

When studying barometers, it's important to understand the following key concepts:

Atmospheric Pressure: Learn how changes in atmospheric pressure are related to weather patterns and altitude.
Reading and Interpreting Barometric Readings: Practice reading and interpreting the measurements displayed on both mercury and aneroid barometers.
Applications of Barometric Measurements: Understand how barometric pressure measurements are used in different fields and industries.

Practice Exercise:

Calculate the difference in atmospheric pressure between two locations based on the given readings from a mercury barometer:

Location A: 29.92 inches
Location B: 30.15 inches

Solution:

The difference in atmospheric pressure is calculated by subtracting the lower reading from the higher reading:

Difference = 30.15 inches - 29.92 inches = 0.23 inches

So, the difference in atmospheric pressure between the two locations is 0.23 inches.

By understanding the principles of barometers and practicing related exercises, you can gain a thorough understanding of this important scientific instrument and its applications.

◂Math Worksheets and Study Guides Seventh Grade. Applying Percents

The resources above cover the following skills:

Number and Operations (NCTM)

Understand numbers, ways of representing numbers, relationships among numbers, and number systems.

Work flexibly with fractions, decimals, and percents to solve problems.

Grade 7 Curriculum Focal Points (NCTM)

Number and Operations and Algebra and Geometry: Developing an understanding of and applying proportionality, including similarity

Students extend their work with ratios to develop an understanding of proportionality that they apply to solve single and multi-step problems in numerous contexts. They use ratio and proportionality to solve a wide variety of percent problems, including problems involving discounts, interest, taxes, tips, and percent increase or decrease. They also solve problems about similar objects (including figures) by using scale factors that relate corresponding lengths of the objects or by using the fact that relationships of lengths within an object are preserved in similar objects. Students graph proportional relationships and identify the unit rate as the slope of the related line. They distinguish proportional relationships (y/x = k, or y = kx) from other relationships, including inverse proportionality (xy = k, or y = k/x).