Lesson 5: Lifting Lever

The three classes of levers differ in the position of the fulcrum relative to the lifting and resistance forces. A second class lever has the fulcrum at one end, the resistance force in the middle, and the effort force at the opposite end of the plank. Can you lift yourself up to the task of investigating levers?

Doing the science

1. Start the Machines Simulation by clicking on the "Sim" tab.
2. Click the "Levers" button at the bottom of the screen.
3. Click the number "2" to select the second class lever from the three numbered buttons at the bottom of the screen.
4. Use the Newton Converter button at the bottom right-hand corner of the screen if you need help converting the hanging mass from kilograms to newtons for the Force on Mass column.
5. Click the green "Pull" button on the Force Device on the right side of the screen.
6. Note and record in Table 1 the height the 1.0-kg mass lifts off the ground, the applied force and height moved that is displayed on the Force device. Please note that the Force Device remains at the 8.0-meter mark throughout the investigation.
7. Click the "Reset" button.
8. Click the red arrow to move the 1.0-kg mass to the 2-meter mark on the plank.
9. Repeat steps 4 - 7, making sure to note and record your data in Table 1.
10. Move and test the 1.0-kg mass at the following positions on the plank: 3, 5, and 6-meter marks.
11. Make sure to note and record your data in Table 1.
12. Click on the 2.0-kg mass to replace the 1.0-kg mass on the plank. Repeat the entire experiment with the 2.0-kg mass.