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Activity –Demonstrating Energy Conversion Efficiency
Purpose
In this activity, we will explore the concept of energy efficiency and identify the key
features of a system that may make the system more or less efficient. Styrofoam
peanuts are used to simulate energy. Energy transfers and conversion processes are
simulated by students passing handfuls of peanuts between each other. The efficiency
of different types of systems are calculated and compared.
Materials and Supplies

Paper bags ~1/2 – 2/3 full of Styrofoam peanuts (one per team)

kitchen-type scale for measuring mass of bags (one per class)

Extra paper bags (one per team)

Stop watch or timer (one per class)
Procedure
The goal is to move your peanuts (energy) as quickly as possible from your energy
source (fuel) to your energy sink (use). The diagram below shows the general setup of
the activity.
1. Break into teams of 4-5 students
2. Measure the mass of the “energy” source (all groups should start with a similar
mass of peanuts in their bag)
3. Define your system process (only hands can be used to transfer the peanuts, no
other tools)
a. Trial 1: Create a simple process – for example, one person at a time
scoops big handfuls of peanuts to move towards the user (second bag)
b. Trial 2: Multi-step process – for example many energy transfers between
students on the team as the peanuts are passed to the user
c. Trial 3: Complicated process – for example the “conversion process”
requires the student transferring the peanuts to spin as they walk, crawl,
etc.
4. Wait for your teacher to start each trial (all teams will go at once). Your goal is to
move as many peanuts as rapidly and efficiently as possible. The teacher will
use his/her discretion in providing 1-2 minutes for each trial (this will depend on
size of area used, amount of peanuts per bag, number of students etc.)
5. At the end of each trial, measure the mass of the bag and peanuts that makes it
to your “user” and any that are still remaining in your source bag. Note the
amount of peanuts lost (e.g., on the floor) for each trial.
6. Refill the source bags to their original mass of peanuts to begin the next trial
Copyright © 2011 Clarkson University, Office of Educational Partnerships
revised 08/11
www.clarkson.edu/k12
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7. Calculate the efficiency of each trial
8. Answer the discussion questions
Example energy transfer and conversion processes for each trial
Energy
Source 1
Sink 1
(energy user)
Energy
Source 2
Sink 2
(energy user)
Energy
Source 3
Sink 3
(energy user)
Results
Fill in the table on the following page as you complete your trials.
Discussion Questions:
1. Was any system 100% efficient? If yes, what was done to make it so?
2. Which were the least efficient systems? Why?
3. What contributed to greatest losses? Describe.
4. What happens to the “energy” (as represented by peanuts) that is “lost”?
Copyright © 2011 Clarkson University, Office of Educational Partnerships
revised 08/11
www.clarkson.edu/k12
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Results Table for energy efficiency activity
Trial
Description of system
Peanuts in
starting bag
(g)
Peanuts
remaining at
source (g)
Peanuts in
ending bag
(g)
1
2
3
Efficiency is calculated as: Efficiency (%) 100 
Copyright © 2011 Clarkson University, Office of Educational Partnerships
Useable energy output
.
Energy value in
revised 08/11
www.clarkson.edu/k12
System efficiency
(%)