Converting figures from the U.S. standards of measures to the metric system may be accomplished with a simple, straightforward process or with an alternative that uses dimensional analysis and is slightly challenging. Using the latter, once you know your equivalent units, you may define a problem logically, canceling out all the units of measure until you’re left only with the ones you’re looking for and your answer.

## Simple Conversion

Convert one mile to meters: One mile equals 1609.344.

Convert one hour to minutes: One hour equals 60 minutes.

Convert one minute to seconds: On minute equals 60 seconds.

Multiply the 60 minutes in an hour by the 60 seconds in a minute to obtain the number of seconds in an hour: 60 X 60 equals 3,600 seconds.

Divide the number of meters in a mile (1,609.344) by the number of seconds in an hour (3,600): 1,609.344 divided by 3,600 equals 0.44704. One mile per hour equals 0.44704 meter per second.

## Dimensional Analysis

Move from the U.S. system of measurement to the metric system. To get from miles to meters, begin by determining the metric equivalent for one mile. One mile equals 1609.344 meters, therefore one mile per hour equals 1609.344 meters per hour.

Start setting up your dimensional analysis. The goal is to reach meters per second and to eliminate all other unwanted units of measurement along the way. You have this information:1609.344 meters per hour. Get rid of the hour as a unit of measure. It is in the denominator position, so bring it in again—this time as a numerator—to be able to cancel it out later:

1609.344 meters per hour X one hour equals 60 minutes.

Finish setting up your analysis by "getting rid of" minutes and adding in seconds:

1609.344 meters per hour X 60 minutes X 60 seconds.

Write the problem so you can clearly see the relationships of all the numbers:

(1609.344 meters X 1 hour X 1 minute) / (1 hour X 60 minutes X 60 seconds)

Cancel all the redundant units of measurement. These will be all the units found on both the top and the bottom of the problem (in the numerator and the denominator positions). You may eliminate the hour and minutes, leaving meters per second. Finish calculating your problem: One mile per hour = 0.447 meters per second.

#### References

- "Math and Dosage Calculations for Health Care"; K.A. Booth and J.E. Whaley; 2010.
- Metric conversions: Metric conversion calculators and tables for metric conversions

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