Melting Chocolate and Energy Efficiency
Categories: Chris Shing, [Lessons]
Tags: chris shing, energy, incandescent, LED, lesson, Science
Content/Topic:
Science: Scientific Method, Energy Efficiency
Objective:
In this experiment the students investigate the term “energy efficiency” and why incandescent light bulbs are less “energy efficient” compared to light emitting diodes (LEDs) through melting chocolate. The lesson teaches students about the scientific method.
Description:
The activity is a demonstration of the inefficiency of incandescent light. Incandescent light bulbs require heat to generate light, which means not all electrical energy is used efficiently. This is shown by the fact that the incandescent light melts chocolate faster than the LED light. This activity is written around the scientific method asking the students to understand why this phenomena occurs. First the students are asked to complete some vocabulary. After the students are asked to understand the problem and formulate a hypothesis to solve the problem. The students then watch the demo and receive/record the information. The students are then asked to formulate a conclusion why the chocolate melted and then reason as to what the term “energy efficiency” means.
Materials:
1 Incandescent lightbulb (40W), 1 LED lightbulb (40W), 2 lamps (of similar type), 2 chocolate bars, 2 rulers, 2 thermometers, 2 light meters or 1 Incandescent lightbulb (40W), 1 LED lightbulb (40W), 2 lamps (of similar type), 2 chocolate bars, 2 rulers, 1 Arduino Uno, 1 SD Logger, 2 Temperature Sensors, 2 LIght Sensors, 1 Laptop
Preparation:
The entire demo can be set up in advance.
Time needed to conduct lesson:
The entire lesson takes approximately 1.5 class periods (where each period is 40 minutes). However, parts of the lesson can be completed before and after the class. The students can fill in the vocabulary and answer the conclusion questions prior to the lesson and after the lesson.
Grade level:
Elementary, Middle
Pros:
It is a demonstration that surprises the students and the chocolate can be eaten afterwards.
Cons:
The initial costs are expensive ($100+). Depending on the users’ skills the setup can be difficult. However, after the initial setup the lesson is easy to repeat.
Lessons and Worksheets
Experiment Data Sheet
Code for Arduino (save as a .pde file after download)
