Investigating Lightbulbs

Transcription

1 Investigating Lightbulbs OVERVIEW In this lesson, students consider the various ways we illuminate our world. They conduct a scientific experiment to determine how much thermal energy various types of lightbulbs emit and consider the pros and cons of each light source. When they see that some types of bulbs are far more energy efficient than others, they consider the environmental implications of those more efficient options hazardous waste. As students review the cost, energy use, lifespan, and disposal requirements of different kinds of bulbs, they learn that making thoughtful, considered choices about the products we use is an important aspect of sustainable intelligence. KEY OBJECTIVES FOR STUDENTS: Identify three types of lightbulbs. Evaluate the pros and cons of three different types of lightbulbs. Carefully consider the implications of choosing different types of lightbulbs. ESTIMATED TIME NEEDED (MINUTES): 50 minutes PRIMARY SUBJECTS: Civics and Government SECONDARY SUBJECTS: Economics, Environmental Education, History, Science GRADE LEVELS: 7, 8 TOPICS: incandescent, compact florescent lamp (CFL), light-emitting diode (LED), energy efficiency, energy conservation, illumination, heat, thermal energy METHODS: 1

2 Brain-Based Learning, Multi-Disciplinary, Multiple Intelligences, Real-World Application, Technology Integration SKILLS: Collaboration, Critical Thinking, Systems thinking VALUES: Curiosity, Mindfulness, Optimism 2

3 PREPARE BACKGROUND INFORMATION FOR TEACHERS: This lesson encourages students to pay attention to something they may not ever have given much thought to before: lightbulbs. In so doing, they learn valuable information about how to ask good questions and consider long-term effects of even the smallest items they purchase and use regularly. Because lighting is a huge part of our energy expenditure, students gain valuable information to help their parents or guardians make informed choices. More important, however, they learn how to approach the things they buy and use regularly with a questioning mind and with sustainable intelligence. PREVIOUS SKILLS NEEDED: Familiarity with the scientific method is helpful. IN ADVANCE: Collect the lab supplies in advance. Lamps can likely be borrowed from other teachers. Bulbs of the various types can be collected from around the house, borrowed from parents or colleagues, or purchased from a home improvement store. In order to make valid comparisons, ensure that the bulbs are roughly the same age (preferably, all are new) and equivalent in brightness (measured in lumens). For example, if you change the recommended bulbs to use a 100W incandescent bulb, you will need a 16 20W LED and a 23 30W CFL. Set up a demonstration station near an electrical outlet. Ideally, you would have at least three lamps so students could investigate all three types of bulbs at the same time. However, if you have only one lamp, you could have students check the bulbs one at a time and allow extra time. If you have easy access to plenty of bulbs of the three different types, numerous lamps, and plenty of electrical outlets, you could set up multiple workstations and have students conduct this activity in smaller groups. Prior to the lesson, establish a safety protocol to address any broken CFL or LED bulbs. Read through the lesson and worksheet in advance, and adapt the information as necessary to reflect current costs and wattages in your area. Also make a copy of the Investigating Lightbulbs Worksheet for each student. MATERIALS NEEDED: 60W incandescent bulb 13W CFL bulb 10W LED bulb 3 lamps 3 electrical outlets Hot pad/oven mitt (to protect hands from hot lightbulbs) Thermometer or temperature probe Timekeeping device Cloth towel (in case of dropped bulb) 3

4 KEY VOCABULARY: incandescent compact florescent lamp (CFL) light- emitting diode (LED) energy efficiency energy conservation illuminate heat thermal energy SAFETY INFORMATION: If students handle the bulbs at any point, remind them to use care. Caution students not to touch lit bulbs under any circumstance, as they may be very hot especially the incandescent bulbs. Also, CFL and LED bulbs are considered hazardous waste. In the event that a CFL or LED bulb is dropped and breaks, cover it immediately with a cloth towel, evacuate students from the room, and contact the administration. The fragments should be cleaned up and properly disposed of immediately because mercury and other dangerous chemicals can disperse throughout the room. 4

5 TEACH ACTIVITY OUTLINE: Time Exercise Description 10 min. Introduction Introduce the lab, and review lab safety. 30 min. Activity Students investigate lightbulbs and complete their worksheets. 10 min. Wrap-Up Students discuss results and answer Reflection Questions. IMPLEMENTATION: 1. Introduction: Ask: Are all lightbulbs the same? In other words, do they all use the same amount of energy and produce the same amount of light? (No. There are different kinds of bulbs and different wattages.) Ask: Do you think understanding the differences in... DIFFERENTIATION: Before starting the activity, you could encourage advanced students to make predictions about which bulbs will be most efficient and why. Then they could repeat the activity on their own at home with several different types and wattages of bulbs, using the scientific method to guide their process and their data collection. 5

6 REFLECT REFLECTION QUESTIONS: Use the following questions to prompt critical thinking and guide students to reflect about the lesson: Why are there so many options for lighting? (We use light in many different ways for example, people are generally more comfortable and relaxed in white-light settings, but... 6

7 EXTEND COMMUNITY CONNECTIONS: Find out who at your school is most informed about purchasing and maintaining the various types of lighting at the school (buyer, maintenance manager, custodian, etc.), and invite that person to the classroom to visit with students about the school s lighting. Beforehand, have students take notice of some of the lighting options currently used around the school and apply what they ve learned about lightbulbs to prepare questions in advance. Encourage students to draft recommendations for improving energy efficiency or disposal and to share their ideas with the visitor during or after the visit. 7