Vernier Software and Technology
Vernier Software & Technology

First-Class Levers

Figure from experiment 2 from STEM 2 with Vernier and LEGO® MINDSTORMS® NXT


A lever is a simple machine used to make work easier. It can help you move heavy objects by increasing the force you exert. A lever consists of a long, rigid bar with a support that allows the bar to pivot. The point where the bar pivots is the fulcrum. There are three classes of levers: first, second, and third. A first-class lever looks like a seesaw. The effort (applied) force and resistance force (load) are at opposite ends with the fulcrum somewhere in between. Crowbars and scissors are examples of first-class levers. In a second-class lever, the effort force and the fulcrum are at opposite ends with the load in between. Wheelbarrows and nutcrackers are examples of second-class levers. When you do a pushup, your body is acting like a second-class lever with your toes as the fulcrum helping to lift your entire weight with your arms. In a third-class lever, the effort force is between the fulcrum and the load. Baseball bats, oars, and shovels are examples of third-class levers. Mechanical advantage (MA) is a value that tells the number of times a lever increases your effort force. Actual mechanical advantage (AMA) includes friction losses, while ideal mechanical advantage (IMA) does not. The difference between the ideal and actual mechanical advantage is a measure of the lever’s efficiency.


In this experiment, you will

  • Use a Force Sensor and NXT to measure the effort force required to pull a lever.
  • Compare actual mechanical advantage and ideal mechanical advantage.
  • Make conclusions about levers.

Sensors and Equipment

This project/activity features the following Vernier sensors and equipment.

Additional Requirements

You will also need NXT Sensor Adapter and a LEGO MINDSTORMS NXT robotics system.

STEM 2 with Vernier and LEGO® MINDSTORMS® NXT

See other experiments from the lab book.

2First-Class Levers
3Audio Assistant
6String Tension Tester
7Gas Pressure
8Yeast in Action
9Grip Strength
10Cartesian Diver
12Lemon Battery
13Battery Tester
14Solar Cells
15Solar Tracker
16Mapping a Magnetic Field
18Migrating Robot
19Magnet Finder
20Mine Sweeper

Project/activity 2 from STEM 2 with Vernier and LEGO® MINDSTORMS® NXT Lab Book

<em>STEM 2 with Vernier and LEGO<sup>®</sup> MINDSTORMS<sup>®</sup> NXT</em> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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