9.3 Moments, Levers, and Gears

• The magnitude of a moment depends on the force applied and the distance from the pivot.


  True
• Force is measured in Newtons (N) and denoted by F.

  True
• What is the formula for calculating moments?

  Moment = Force x Distance
• The fixed point around which an object rotates is called a pivot
• The fixed point around which the lever pivots is called the fulcrum
• A seesaw is an example of a first-class lever.


  True
• Factors affecting the magnitude of a moment

  1️⃣ Force applied

  2️⃣ Distance from pivot
• Match the quantity with its unit and symbol:

  Moment ↔️ Newton-meters (Nm) ||| M

  Force ↔️ Newtons (N) ||| F

  Distance from pivot ↔️ meters (m) ||| d
• What categorizes the different classes of levers?

  Arrangement of fulcrum, load, effort
• Mechanical advantage is the ratio of the load to the effort
• What is the formula for calculating the mechanical advantage of a lever?

  Effort Distance / Load Distance
• Gears transmit rotational motion using toothed wheels
• Gears can be used to increase or decrease the rotational speed
• The formula for calculating moments is Moment = Force x Distance from pivot
• The pivot in moments is the fixed point around which an object rotates
• In a first-class lever, the fulcrum is between the load and the effort
• Arrange the lever classes based on the position of the fulcrum relative to the load and effort.

  1️⃣ First class: Fulcrum between load and effort

  2️⃣ Second class: Load between fulcrum and effort

  3️⃣ Third class: Effort between fulcrum and load
• What is the arrangement of a second-class lever?

  Load between fulcrum and effort
• The principle of moments states that the sum of clockwise moments equals the sum of anticlockwise moments for a lever in equilibrium.


  True
• What does mechanical advantage measure in a lever?

  Multiplication of force
• What is the smaller gear in a gear system called?

  Pinion
• The gear ratio determines the relationship between the rotational speeds of two gears
• What is a moment in physics?

  Turning effect of a force
• What is the unit for measuring moments?

  Newton-meters (Nm)
• What is the term for the push or pull exerted on an object?

  Force
• The distance from the pivot is measured in meters
• The distance from the pivot is denoted by the symbol d
• A force applied far from the pivot creates a larger moment.


  True
• Levers come in three classes based on the arrangement of the fulcrum, load, and effort.


  True
• The fixed point around which a lever pivots is called the fulcrum
• A moment is the turning effect of a force around a pivot
• What is the unit for measuring moments?

  Newton-meters (Nm)
• A seesaw is an example of a first-class lever.


  True
• Steps to apply the principle of moments to a lever

  1️⃣ Sum of clockwise moments

  2️⃣ Sum of anticlockwise moments

  3️⃣ Load x Load distance = Effort x Effort distance
• The mechanical advantage (MA) is the ratio of the force exerted by the lever (load) to the force applied
• A mechanical advantage of 5 means the lever multiplies the applied force five times.


  True
• A larger gear rotates at a slower speed than the pinion in a gear system.


  True
• Increasing the distance from the pivot increases the magnitude of the moment.

  True
• A force of 50 N applied at a distance of 0.3 m from the pivot creates a moment of how many Nm?

  15 Nm
• A seesaw is an example of a first-class lever.


  True