Activity - Gummy Bears in Space
Materials needed: 24 in x 6 in x 1in wood board, 2 tongue depressors, two rubber bands, pencil,
2 yard sticks, 40 gummy bears
Introduction
How would you design an experiment to optimize (yield) distance?
Focus on 1) Best angle of board
2) Best position on board
Basic Concepts of Experimental Design
Experimental Unit (EU): Gummy bears
Treatment: Launch Positions (formed by combining levels of each factor, ex: low angle,
front position)
Factor (1): Launch angle
Levels: Low, Medium, High
Factor (2): Launch position
Levels: Front, Back
Replication: Fallacy about multiple readings being true is the inconsistencies that occur.
For example, measurements could be taken by several different people with
different standards. To minimize variation, have only one person measure.
Control for outside influences. Do to limited time, budget, etc, the designer may
need to block for more local control.
Randomization must occur to eliminate biases. To Completely Randomize, the launch
order needs to be in a random order besides the obvious initial need to
randomly assign the Gummy bears
Experimental Design:
The 30 Gummy Bears* need to be assigned a randomly generated number of 1 -30.
Assign #1-5 to the low angle and front position, assign #6-10 to a medium angle and
back position, etc. Now, randomly assign the angle and position combination a number
of 1-6. Randomly generate which particular angle/position will be experimented on first.
Repeat, until each of the six combinations have been completed.
Angle
Low
Low
Med
Med
High
High
Position
Front
Back
Front
Back
Front
Back
Gummy Bears
# ________
# ________
# ________
# ________
# ________
# ________
Consistency is essential.
Mark the following positions: (1) fulcrum position of pencil on depressor
(2) Gummy bear launch position on depressor
(3) front of board on floor
(4) trace depressors F/B centered positions on board
(5) position where books touch underside of board
Only one person can (1) launch
(2) hold books and launch board steady
(3) measure (or have two agree to a single measure)
Agree upon sitting, lying, ... position of Gummy bear upon launch ahead of time
and be consistent.
*Note*: If there is a variation in Gummy bears’ weight and size, it will need to be ignored
for now. This needs to be kept simple for our competition.