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.
Transmission Gear Ratio (R1): denotes how many engine revolutions there are for each driveshaft revolution. Differential Gear Ratio (R2): denotes how many driveshaft revolutions there are for each axle revolution. Now, we'll derive the equation: If the engine speed (for this example) RPM = 6000 revolutions/minute, then the driveshaft speed is the engine speed divided by tranny gear ratio R1 = ( 6000 / R1) revolutions/minute, and the rear axle speed is the driveshaft speed divided by rear-end ratio R2 = ( 6000 / (R1*R2) ) revolutions per minute.