Lesson 1: Lifting Lever

Is it possible for you to lift up something that weighs much more than you do? It is! One of the simplest ways to do this is by using a type of machine called a lever. A lever is a stiff plank or bar with an object or point that the plank rests on. Lift yourself up and start this simulation.

Here are some definitions to help you in your investigation.

Machine - a device that can change the force on, the distance moved, and/or the speed moved of an object

Lever - a simple machine made up of a plank and a fulcrum

Fulcrum - a point or object a lever rests on

Plank - a long, flat piece of wood or other similar material

Force - any push or pull on something

Newtons (N) - a unit of measure of force

Effort Force - a force that is applied by a person on an object. This is also called the lifting force.

Load - something that is being lifted or moved. Also called the resistance force because the load resists moving.

Balanced Forces - two or more forces that cancel each other out. The forces are opposite in their direction, but equal in size.

Mass - the amount of matter in an object

Kilograms (kg) - a unit of measure of mass

Work - the transfer of energy by a force acting on an object that is being moved

Doing the science

Part I. First Class Lever. A first class lever is one where the fulcrum is in the middle of the effort force and the load or resistance force.
1. Start the Machines Simulation by clicking on the “Simulation” tab.
2. Click the “Levers” button at the bottom of the screen.
3. Make sure that the number “1” (first class lever) is selected 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.
7. Click the “Reset” button.
8. Click the left red arrow to move fulcrum to the 3-meter mark on the plank.
9. Repeat steps 4 - 7, making sure to note and record your data in Table 1.
10. Click the right red arrow to move the fulcrum to the 5-meter mark on the plank.
11. Repeat steps 4 - 7, making 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.