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.
A transmission uses toothed gears that interact with each other in order to produce torque, and the gear ratio refers to the gearsâ relation to each other. Say you have an input gear with 20 teeth that interacts with an output gear that has 10 teeth. In order to spin the gear with 20 teeth once, the 10 tooth gear must make two full rotations. A gear ratio is calculated by taking the number of teeth on the output gear and dividing it by the input gear. Thus the gear ratio in this example is 1:2 but itâs usually simplified to 0.5:1 in order to tell how many times the output gear must rotate for the input gear to make one full rotation. There are many gears in the transmission with different sizes, which allows for many gear ratio combinations.