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.
1 They make it possible to determine exact gear ratios. 2  You just count the number of teeth in the two gears and divide. 3  So if one gear has 60 teeth and another has 20, the gear ratio when these two gears are connected together is 3:1.his explains why two gears, one half as big as the other, have a gear ratio of 2:1. The smaller gear has to spin twice to cover the same distance covered when the larger gear spins once. Most gears that you see in real life have teeth. The teeth have three advantages: 1  They prevent slippage between the gears.