An output gear has 10 teeth and an input gear has 40 teeth. What is the mechanical advantage of his gear combination? Is force or speed multiplied in this example?

In thsi problem, we are given two number of teeths of two gears: one is input and one is output. To create motion using two different sized gears, we make use of the gear reduction ratio which is the ratio between the driven gear teeth of the output and the driven gear teeth of the input. In this problem, the gear reduction is equal to 10/40 or 1/4. The output torque is the input torque times the gear reduction thus the output torque is smaller than the input. For speed, on the other hand, output speed is equal to input speed divided by the gear reduction. hence, force is larger in the output than the input.