Human Powered Flashlight Challenge
Subject: Physics
Grade Level(s): Grade 4
Big Idea(s):
- Students know the role of electromagnets in the construction of electric motors, electric generators, and simple devices, such as doorbells and earphones.
- Students know electrical energy can be converted to heat, light, and motion.
- Students know magnetic materials and electric currents (moving electric charges) are sources of magnetic fields and are subject to forces arising from the magnetic fields of other sources.
What you need: • Hand crank generator
• Long alligator jumpers
• 1 D Battery
• 1 light bulb holder
• 1 small light bulb
Setting: Classroom
Time Needed: Teacher’s Discretion
Summary:
In this activity we will build a human powered flashlight. This should reinforce what we have learned about circuits and give us an opportunity to explore how an electric generator works.
Learning Goals / Objectives:
- Students will gain a hand on understanding of how mechanical motion is used to generate electricity.
Background
This activity is relatively bullet proof.’ For completion, it is important to move from this to a model of how an electric generator works (“Virtual Devices” … stay tuned).
Safety
This activity has little to no risk associated with it.
Setup:
Make sure you have the following:
- Hand crank generator
- Long alligator jumpers
- 1 D Battery
- 1 light bulb holder
- 1 small light bulb
Anticipatory Set:
1. How can you utilize electric energy?
2. How can you generate electric energy?
Instructions / Activities:
Your goal: Remake the flashlight (from DC Circuits and the Flashlight Challenge) using human power.
Assessment:
Teacher’s Discretion
Wrap-up / Closure:
- Why does the bulb light up?
- Does the _speed at which you crank the generator affect the light output
- How do you think the hand crank generator works? Sketch a model if you can.
