Levers

ACTIVITY HEADER

 

 

 

Name of Activity

Levers

Author

Laurie Cormler

Keywords

levers, found materials, Simple Machines

Subject

Simple Machines

Grade Level

4, 5, 6

Time

1 Hour Total

Brief Description

Students will explore the different classes of levers using simple classroom materials.

Lesson Objectives:

- Familiarize students with levers, a type of simple machine.

- Teach students about the usefulness of levers and how they are applied in the real world.

- To introduce vocabulary associated with levers.

Materials Needed:

- Lever worksheet.

- LEGO Simple Machines kit.

Preparation and Set Up:

- Make enough copies of the worksheet for each student.

- LEGO Simple Machines kit.

- Arrange students in groups.

- Distribute materials.

Necessary Background

There are three classes of levers:

Class 1 levers:

- Have the load and effort at the two ends and the fulcrum in the middle.

- Examples include: scissors, seesaws, pry bars.

Class 2 levers:

- Have the effort at one end, the load in the middle and the fulcrum at the other end.

- Examples include: nut crackers, bottle openers, doors, and wheel barrows.

Class 3 levers:

- Have the load at one end, the effort in the middle and the fulcrum at the other end.

- Examples include: fishing pole and hockey stick.

The WORK on either side of the fulcrum is equal to the distance from the fulcrum times the force applied (weight of the object). For levers to balance the work on one side must equal the work on the other side – Force1 * Distance1 = Force2 * Distance2.

Vocabulary:

levers

first class levers

second class levers

third class levers

simple machines

fulcrum – balance point/point that lever move around (center of gravity)

effort – force needed to lift load

load – object being lifted

Procedure

  1. Explain to the class the concept of levers. Use the powerpoint attached to explain the three classes of levers, fulcrums, effort and load.
  2. Explain how levers are useful in our everyday life and give some examples.
  3. Pass out the Lever Activity Worksheet
  4. Have students construct levers out of materials in their LEGO Simple Machines kits
  5. following instructions on the worksheet.
    1. Must design the placement of the fulcrum. The fulcrum must be off the surface of the table.
    2. Design must be sturdy
    3. Fulcrum must rotate freely
    4. Use the weighted brick in the kit as the load, place this at one end of the lever.
    5. Students will lift the weighted brick by applying effort to the opposite end of the lever.

  • Let students experiment with the placement of the fulcrum, load and effort.
  • Bring the class together and discuss how students were able to lift a load with the least amount of effort. Ask:
    1. What conditions made it easiest to lift your load?
    2. What building difficulties did you come across?

    Extensions or Modifications:

    - Students can use their lever to accomplish a specific task, e.g., lift a LEGO person to the top of a wall.

    - Explore different locations for a fulcrum.

    - Turn the lever into a catapult.

    Reference 1

    http://sites.tufts.edu/stompactivitydatabase/files/formidable/lev1.doc

    Reference 2

    http://sites.tufts.edu/stompactivitydatabase/files/formidable/lev2.pdf

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