Electrical Energy
Recommended for grades 9–12.
Introduction
In this experiment, you will study a small, inexpensive electric motor used as a crude elevator. You will measure the current through, and voltage across, a motor as it lifts a small mass. If you know the current and voltage, you can calculate another electrical quantity – power. The power used by an electrical device can be calculated from
The unit of power is the watt (W). An electrical device that uses 1 W converts one joule of energy to another form every second (1 J/s). If the power provided to a device is constant over time, you can multiply the power by the time and get the energy. If the power provided to a device changes during the experiment, the electrical energy can be determined by finding the area under a power vs. time graph.
Objectives
- Measure the power and electrical energy used by an electric motor.
- Measure the gain in potential energy of a mass lifted by the motor
- Calculate the efficiency of the motor.
- Study the efficiency of the electric motor under different conditions.
Sensors and Equipment
This experiment requires each of the following Vernier sensors and equipment (unless otherwise noted):
Additional Requirements
You may also need an interface and software for data collection. What do I need for data collection?
Download Experiment Preview
The student-version preview includes:
- Step-by-step instructions for computer-based data collection
- List of materials and equipment
Note: The experiment preview of the computer edition does not include essential teacher information, safety tips, or sample data. Instructions for Logger Pro and other software (such as LabQuest App or TI handheld software, where available) are on the CD that accompanies the book. We strongly recommend that you purchase the book before performing experiments.
Standards Correlations
Included in the Lab Book
Vernier lab books include a CD with word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.