What explains the result?
A cornstarch suspension can resist sudden stress and flow more easily under slow movement; it is a non-Newtonian mixture.
PHYSICAL SCIENCE · GRADES 4–8
Oobleck force test
INVESTIGATION QUESTIONHow does the cornstarch-to-water ratio change how far a marble sinks in five seconds?
● ILLUSTRATIVE SCIENCE MODEL
ENGLISH CAPTIONS
Prepare three measured ratios. Each batch is a particle suspension; changing the ratio changes its water content.
0.0 / 3.0 s
Where does this matter?
Shear-thickening materials inspire protective gear and impact-resistant materials.
What should you keep in mind?
Illustrative sink depths depend strongly on water content, mixing, marble size, and timing. Keep the actual recipe consistent and do not pour it down a drain.
CORNSTARCH SUSPENSION · RATIO TEST · GRADES 3–8
Is it a
solid or liquid?
Prepare three starch-to-water ratios, gently release the same marble, and record how far it sinks in five seconds. Then compare that slow response with a quick tap.
FIVE-SECOND MARBLE TEST1.5:1 RATIO
MARBLE SINKREADY
SELECTED MIX1.5:1 STARCH : WATER
Same marble · same releaseMeasure depth after 5 seconds
MAKE SENSE OF THE PATTERN
What can a ratio comparison tell you?
Oobleck is a suspension: tiny starch particles are dispersed in water. Changing the ratio changes how closely packed those particles are and how the mixture flows. Under a quick force, particles can jam temporarily; under slow movement, they can slide past one another. The model’s sink-depth values are only illustrative—actual outcomes depend on the recipe, mixing and timing.
MODEL RUNSRun each ratio to complete the visual comparison.
Real-world connection: Researchers study shear-thickening suspensions for impact protection. Oobleck itself is not protective equipment, and this short classroom test cannot evaluate product safety.