Footwear impression marks { the mark made by the outside surface of the sole of a shoe (the. outsole) { are distinctive patterns often found at crime scenes. They are among the most. commonly found evidence at crime scenes and present more frequently than ngerprints.
Start with a two-gear train. To be able to determine a gear ratio, you must have at least two gears attached to each other â this is called a gear train.. Usually, the first gear is a drive gear attached to the motor shaft and the second is a driven gear attached to the load shaft.. Divide the teeth numbers of the drive and driven gears. The important thing to remember when dealing with gear trains with more than two gears is that only the driver and driven gears (usually the first and last ones) matter. In other words, the idler gears don't affect the gear ratio of the overall train at all.
The fact that one gear is spinning twice as fast as the other results from the ratio between the gears, or the gear ratio (Check out our gear ratio chart for more info). In this figure, the diameter of the gear on the left is twice that of the gear on the right. The gear ratio is therefore 2:1 (pronounced two to one). If you watch the figure you can see the ratio: Every time the larger gear goes around once, the smaller gear goes around twice. You can see that if both gears had the same diameter, they would rotate at the same speed but in opposite directions.