Simple Machines Continued: Gears and Friction
Gears Explain what gears are. (p. 20) What materials are gears typically made of? (p. 20) What are gears typically used for? (p. 20) List at least four example of real-life machines that use gears. Explain what a gear train is. Quickly sketch a simple two-gear train. (p.20/figure 5) Explain what a gear ratio is. (p. 20) A bicycle is an example of a two-gear train connected by a chain. If your front (driver) gear has 10 teeth, and the follower (back) gear has 50 teeth, how many times must your pedal the front gear around to have the back gear rotate once? Explain how you know. (figure 5) If your front (driver) gear has 60 teeth, and the follower (back) gear has 15 teeth, how many times will the rear gear rotate when the front gear turns once? Explain how you know. (figure 6) Fill in the blanks. With a __________ gear ratio, the gear can be turned with less ________ but must go a longer __________. (figure 6a) Fill in the blanks. With a __________