1.2

• complex machine - a machine that has several parts that work together to perform a task, such as a bike
• • System - a group of parts that work together to perform a general function
• subsystem - a smaller group of parts within a complex machine that performs a specific function
• linkage -  a belt or a chain to transfer energy from an energy source to an object

  • form a direct link between two separate wheels so that when one turns, the other will turn in the same direction
• transmission -

  • type of linkage for transferring the energy from the engine to the wheels in large vehicles such as cars and trucks
  • Contains a number of different gears
• gears - A pair or group of wheels with teeth that interlink; when they rotate together, one gearwheel transfers turning motion to another
• driving gear - the gear that has force applied to it from the outside
• follower gear - the output of the force, turns because the driver gear is turning
• multiplying gears - the driver gear is larger than the follower gear

  • One turn of the large wheel results in several turns of the smaller wheel
  • has a speed advantage
• reducing gears - The driving gear is smaller and has fewer teeth than the follower gear

  •  decrease the turning speed, but less force is needed
• gears on a bike

  • High gear = multiplying gear (going fast, or on flat surface)
  • Low gear = reducing gear (going slow, or uphill)
• parallel gears - driver gear and the follower gears are the same size

  • even number of gears, the direction of motion is reversed from the direction of the driving gear
  • odd number of gears, the direction of motion is the same as the driving gear
  • used to reverse cars