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Part 1 - Step by Step

  1. Instruct Instruct students that they will be investigating the amount of force used to balance the Lever and the location of the pivot point.

    • They will be collecting data by drawing their lever at the three pivot points. Watch the animation below to see how the lever can move at each of the three pivot points. At pivot point 1, the lever is attached to the left, creating a longer right hand length. At pivot point 2, the lever is attached in the center, creating equal left and right hand lengths. At pivot point 3, the lever is attached to the right, creating a longer left hand length.

      Pivot Point adjusted to all three points

  2. Model Model how to detach the beam to adjust the pivot point (left, right, middle). Also, model how to attach pins and other pieces to the disk to add more weight in order to increase force.

    Three disks are shown in a vertical line, with two red pins shown between each, indicating how they can be stacked together with the pins to create stable stacks of Disks.
    Attach Disks with Pins
  3. Facilitate Facilitate a discussion with students as they complete the activity:
    • What pieces do you have to add to the disks when you change the pivot point so that the disks are balanced? Ensure that each group is investigating each of the three pivot points on the Lever (left, right, middle).
    • Ask students to draw their lever at each pivot point position and ask them questions about their build along the way.
    • Ask students, “How does the force on the disks change when the pivot point changes? Why aren’t the disks balanced each time?”
    • Remind students that 'work' is a task that requires effort to complete. In this Lab, work is done when the Lever is able to move/lift an object.
  4. Remind Remind groups that it may take several tries to build and test their Lever. Trial and effort is a part of the process.
  5. Ask Ask what worked and what mistake did you make when building and testing the Lever. What did that teach you?
    • How could you improve the Lever?
    • How could you improve the trial?

Mid-Play Break & Group Discussion

As soon as every group has accomplished observing and adding pieces to the disks at all three pivot points, come together for a brief conversation.

  • Have groups share their data and drawings from the Blueprint Worksheet with another group.
  • Which pivot point required the least amount of force to balance the Disks?
  • Which pivot point required the most amount of force to balance the Disks?
  • How does your data compare to the other group?

Part 2 - Step by Step

  1. InstructInstruct each group to use the data they collected in Play Part 1 to choose the best pivot point for balancing the Lever. The Lever will have three disks together on one side and VEX GO pieces on the opposite side. The challenge is to use the least amount of additional VEX GO pieces on the opposite side to balance the Lever.
    The Scale Lever build with the pivot point in the center, and the right side magnet empty. The left side magnet is attached to a stack of three disks.
    Three disks on same side of the Lever
  2. ModelModel for students how to attach three disks on the same side of the Lever together using pins and how to press onto the Lever.
    Three disks are shown in a vertical line, with two red pins shown between each, indicating how they can be stacked together with the pins to create stable stacks of Disks.
    Attach Disks with Pins
  3. FacilitateFacilitate the investigation by walking around and asking each group to use their Blueprint Worksheet data. They will use this data to decide on the position for the pivot point to lift the disks and balance the Lever with the least amount of extra pieces.
  4. RemindRemind groups that they are trying to experiment with how a Lever makes work easier by reducing the amount of force needed to lift the Disks.
  5. AskAsk students to share their thoughts, based on their trials and observations, on how a lever can make work easier. On their Lever, was the force on each side of the pivot point the same? How do they know?
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