Second Class Levers

Students use a ruler, a stack of books, and a finger fulcrum to model a class two lever. By placing a load at different points on the lever, they observe how load position affects the effort required to lift it.

1. Stack several books vertically to create a support base.
2. Place one end of a ruler on top of the books to act as the fulcrum.
3. Use your pointer finger to lift the other end of the ruler, providing the effort.
4. Place a weight at the point on the ruler closest to your finger (the effort) and try lifting. Note how heavy it feels.
5. Move the weight to the middle of the ruler between the fulcrum and the effort. Lift again and observe.
6. Place the weight closest to the fulcrum and lift once more. Compare how heavy it feels compared to the other positions.

📄 The Lever Experiment - eSchoolToday: https://eschooltoday.com/learn/class-two-lever-experiment/

📄 Lifting with a Lever - Science Buddies: https://www.sciencebuddies.org/Files/789/4/Classroom_Activity_Teacher_Levers.pdf

• Try using different weights to see if the effect is more noticeable.
• Swap the ruler for a longer or shorter lever and compare results.
• Replace the pile of books with a block, cup, or small box as the fulcrum.

• Ensure the pile of books is stable to prevent the ruler from slipping.
• Use a weight that is not too heavy to avoid dropping it on fingers or toes.
• Supervise younger children to prevent pinched fingers under the ruler.

• Which load position required the least effort to lift? (Closest to the fulcrum.)
• Which load position required the most effort to lift? (Closest to the effort.)
• Why does placing the load near the fulcrum make it easier to lift? (Because it reduces the turning effect, giving the lever a greater mechanical advantage.)
• How does this experiment relate to real tools like a wheelbarrow? (The closer the load is to the wheel/fulcrum, the easier it is to lift and move.)