Lever N Fulcrum: Hanging Mobile STEM Challenge

In this STEM challenge, students will tinker with straws, thread, and cardboard to learn about a load, lever, and fulcrum.

Students will start with two straws with one string tied in a different place on each. The straw represents the lever while the position of the string represents the position of the fulcrum. There will be a straw with the fulcrum in the middle and another with the fulcrum near either of its ends. The students will also be provided with six different weights. The weights are made out of lightweight cardboard as not to bend the straw, but heavy enough to show a significant pull.

Lesson: Simple Machines: Introduction to levers and fulcrums.

Objective: Introducing Class 4 & 5 students to the concept of fulcrums, levers, and simple machines.

Supplies

1) Straws
2) Cardboard

3) Scissors/Cutter

4) Thread

And Of course a Smartphone for clicking photos ;-)

Step 1: Supplies:

1) Straws

2) Cardboard

3) Scissors/Cutter

4) Thread

And Of course a Smartphone for clicking photos ;-)

Step 2: Procedure:

The lesson will start with an investigation of how the location of the fulcrum affects how weight balances on the lever. Students will be given a little time to explore this, and then move into the next activity.

Step 3: Investigation 1: Fulcrum at the Center

With the fulcrum at the center, their task would be to use equally weighted cardboard pieces and try to balance it. Then they will balance differently weighted cardboard pieces.

Outcome:

Students will learn that when the fulcrum is at the center; they have to place the equal weight on each side of the straw to balance it. Moreover, the weights should be equidistant from the fulcrum. They will also note that when they try to balance two different weights, the heavier mass needs to be closer to the fulcrum.

Step 4: Investigation 2: Fulcrum Near One End

With a fulcrum near one of its ends, their task would be to use equal-weighted cardboard and try to balance it. Then they will balance differently weighted cardboard.

Outcome:

Students will observe that when the fulcrum is near the end, to balance it, they have to use differently weighted cardboard with the heavier cardboard on the shorter side.

Step 5: Show Time: Hanging Mobile Challenge

Now that have learned about load, fulcrum and lever and how to balance them. It is time to challenge them.

For their final task, students will be instructed to create a balanced hanging mobile using only the straws, string and weights. They will have to rely on their knowledge of fulcrums and weight balance to complete this task. The straws attach to each other vertically, with their respective string tied to the straw above it. The uppermost straw’s string is for holding the mobile when finished.

Thank you very much for sparing your precious time.