Course Chapters

Mathematics Review

Basic Concepts

Advanced Concepts

Section Tests



Useful Materials



Texas Instruments Calculators

Casio Calculators

Sharp Calculators

Hewlett Packard Calculators


Units Conversion Lookup






Linear Least Squares Regression

Newton's Method Equation Solver

Gas Laws


Contact Webmaster


Area measures the size of a surface using length measurements in two dimensions. An area is being measured if two length units are multiplied such as square inch or square centimeter, or if a special area unit such as acre or hectare is used.

Back to: Units


Density measures how much of a substance is contained in a given volume. Stating this more carefully gives a math clue for determining density's units: Density is the mass per unit volume of a substance. So the units for density are mass units divided by volume units.

Back to: Units


Acceleration is a measure of how fast velocity is changing, so we can think of it as the change in velocity over time. This gives the units clue: velocity over time.

The most common use of acceleration is acceleration due to gravity which can also appear as the gravitational constant (you might have seen it as .)

Back to: Units


Energy is the ability to do work. The SI unit for energy is a joule. One joule is defined as the energy expend by a force of one Newton moving one meter along the direction of the force.

Back to: Units


Volume measures the size of an object (not just the surface) using length measurements in three dimensions. A volume is being measured if three length units are multiplied, such as cubic inch or cubic centimeter, or if a special volume unit such as fluid ounce or liter is used.

Back to: Units


Velocity gives an indication of the speed of an object by measuring the change in position (measured as a length) over time. This gives the crucial clue to the units: distance over time.

Back to: Units


A force is an entity that when applied to a mass causes it to accelerate. Sir Isaac Newton's Second Law of motion states that

the magnitude of a force = mass * acceleration.

This gives the units clue: mass * acceleration.

This combination of units has been given the name Newton (N) in honor of Sir Isaac. The most common use of force is force of an object due to gravity (we call it weight!) which is calculated using mass * gravitational acceleration.

Back to: Units

Developed by
in cooperation with the Department of Chemistry,
The University of North Carolina at Chapel Hill

Copyright © 1996-2008 Shodor
Please direct questions and comments about this page to