This is a very simple unit converter that could be useful to beginning students in most areas of science and engineering. It offers a variety of conversions that include energy, pressure, volume, temperature and mass units. Both SI and English units are addressed.
To teach students how to convert various physical quantities from one unit to another.
Target Student Population:
Anyone involved in unit conversions. Particularly useful for science and engineering students in high school or college.
Prerequisite Knowledge or Skills:
An understanding of the physical quantities and units encountered in physics, chemistry, and engineering.
Type of Material:
An online calculator and reference material.
An online calculator that students might use for problem solving that requires unit conversions in physics, chemistry, or engineering classes.
An internet browser capable of supporting Java applets.
Evaluation and Observation
The calculator appears to be quite accurate in its conversions, and offers a variety of useful unit conversions. In addition, the variables included are certainly some of the principal ones encountered by beginning students in science and engineering.
A serious omission is the conversion of length units. In the energy conversion section of the calculator, it offers Joules and calories but not BTU as a unit. Likewise, in the temperature section Kelvin, Fahrenheit, and Celsius temperatures are offered, but not Rankine. And in the volume section, cubic feet is not one of the units offered. These omissions make it less useful as an engineering calculator.
Potential Effectiveness as a Teaching Tool
The calculator's simplicity and rapid response make it attractive for students and educators alike to use in assignments or classroom activities when unit conversions are being introduced. Another nice feature for both educators and students is its "How it's Done" section which provides the actual conversion factors used by the calculator. Thus, the mystery of the "black box" is removed.
The calculator frequently displays an inordinate number of significant figures in its unit conversions. Although the conversion factors actually used by the calculator employ only 3-6 significant figures, answers are often reported to as many as 15 significant figures. For example 45 Joules converts to 10.755258126195 Calories, and 70?F converts to 21.1111111111111?C. Students using the calculator would have to be cautioned against believing and reporting 15 significant figures in their problem solutions, a common problem with beginning students.
Also, although the conversion factors are shown,
it would be more useful for beginning students if an exqample of an entire conversion calcuation itself were also shown.
Ease of Use for Both Students and Faculty
The calculator is very easy to use with obvious input boxes and radio buttons for entering values and selecting input units. Clear "how to use" instructions are given on the same page.
Abbreviations used for some units might not be clear to the beginning student (e.g. atm, mm Hg, etc). A list of abbreviations and an explanation for each unit would be very useful.
Other Issues and Comments:
Although somewhat limited in scope, this is an easy to use unit converter that could be useful for science and engineering students just learning to convert units.