Topic 2 - The Wheel and Axle, Gears, and Pulleys

Question 1

Winch

Answer 1

• Simple machine with a small cylinder and a crank or handle
• Axle of winch acts as a fulcrum and handle acts like an effort arm
  Ex. Pencil Sharpener

Question 2

Wheel and Axle

Answer 2

• Two turning objects that are attached to each other at their centers
• One object cause the other to turn
• don’t need to have a circular lever handle
  Ex. Wheels - bus, car, doorhandles

Question 3

Subsystems in a Bike

Answer 3

• Wheel and Axle
• Gear Chain/Sproket System
• Levers

Question 4

How do all working parts link and transfer energy?

Answer 4

• All the subsystems are joined or linked together and energy is transferred between those working parts
• If a subsystem is removed the machine will no longer be efficient

Question 5

Gear

Answer 5

• A rotating wheel with teeth around its rim

Question 6

Gear Train

Answer 6

• A group of two or more gears
• Gears move in opposite directions

Driver Gear - First wheel that turns
Folower Gear/Driven Gear - Second gear that turns - turns in reaction to the driver gear

Question 7

Sprocket System

Answer 7

• Two gears tuned by a chain or a rope
• Gears move in the same direction
  Ex. bike

Question 8

Speed Ratio

Answer 8

• Number of driver teeth divided by number of follower teeth

Question 9

Gear Combinations

Answer 9

• The total amount of gears a bike has
• Multiply the front gears sockets with the back gear sockets to find the total amount of gears
  Ex. 6 x 3 = 18

Question 10

Pulley

Answer 10

• A grooved wheel with a rope of chain running along its groove

Fixed Pulley - Attached or fixed to ceiling - doesn’t move
Movable Pulley - Moves with the load

Question 11

Compound Pulley

Answer 11

• Complex system with two or more pulleys

Question 12

Block and Tackle

Answer 12

• Complex system with at least one movable and one fixed pulley