A speedometer tells the driver how fast he's going, but you can also calculate speed with simple arithmetic.
MPH, or miles per hour, is a common unit that describes the speed of a moving object such as a car or truck. If you look at the words themselves, "miles per hour" tells you what sort of information you need to make the calculation and the operation needed to make that calculation: you need to know distance in miles and time in hours, and the "per" lets you know that you need to divide.
Instructions
Average MPH Calculation
1. Determine the distance that the truck has traveled, in miles. You can get this from the truck's odometer or from other information such as the distance between the starting city and the ending city.
2. Determine how long the trip took, in hours.
3. Divide the distance traveled by the time needed to get the average speed in MPH. For example, a 325-mile trip took five hours, so the truck averaged 325 miles / 5 hours or 65 MPH.
Calculating MPH at a Point
4. Measure the length of the truck in feet. Divide the length by 5280 to determine the truck's length in miles. Example: 88 feet / 5280 feet/mile = 0.016667 miles.
5. Use a stopwatch to determine how long, in seconds, it takes the truck to pass a fixed point such as a light post or mailbox. Start the watch when the front bumper passes and stop it when the back bumper passes. Divide the number of seconds by 3600 to convert to hours. Example: 2.2 seconds = 3600 seconds/hour = 0.00061 hours.
6. Divide the length of the truck by how long it takes to pass the point to get its speed in MPH. Example: 0.016667 miles / 0.00061 hours = 27.3 MPH.
Tags: 00061 hours, 016667 miles, bumper passes, Divide length, hours Divide