Fluido Não Newtoniano: Oobleck

Criação de um fluido que espessa por cisalhamento a partir de amido de milho e água

Classroom Demonstrations Beginner (Middle School) 20 min ~$3,00

Objetivo

Criar e explorar um fluido não newtoniano que se comporta tanto como sólido quanto como líquido dependendo da força aplicada.

Contexto

Oobleck is a suspension of cornstarch in water that exhibits shear-thickening (dilatant) behavior. Under slow, gentle force, it flows like a liquid. Under sudden, strong force, the starch particles jam together and it behaves like a solid. This non-Newtonian behavior occurs because the starch particles are suspended at a critical concentration where they can rearrange under slow stress but lock together under rapid stress. The name comes from the Dr. Seuss book 'Bartholomew and the Oobleck.'

Avisos de segurança

  • Cornstarch is slippery when wet — clean up spills immediately
  • Do not pour oobleck down the drain — it will clog pipes
  • Non-toxic but not for consumption

Materiais

  • Cornstarch (400 g)
    About 2 cups
  • Water (250 mL)
    About 1 cup
  • Food coloring (5 drops)
    Optional

Equipamentos

Large mixing bowl Spoon Plastic sheet or tray (to contain mess) Speaker with subwoofer (optional, for vibration demo)

Procedimento

1

Place the mixing bowl on the plastic sheet. Add the cornstarch to the bowl.

2 min
2

Slowly add water while mixing with your hands. The ideal ratio is about 1.5–2 parts cornstarch to 1 part water. Add water gradually until the mixture is the consistency of thick honey.

5 min
3

Test 1 (Slow force): Gently dip your hand in and slowly pull it out. The oobleck flows like a liquid.

3 min
4

Test 2 (Fast force): Punch the surface hard. Your fist bounces off as if hitting a solid.

3 min
5

Test 3 (Shaping): Squeeze a handful quickly into a ball. When you stop squeezing, it melts back into liquid.

3 min
6

Optional: Place the bowl on a speaker playing low-frequency bass. The oobleck forms standing wave patterns and finger-like protrusions.

4 min Protect the speaker with plastic wrap

Resultados esperados

The oobleck flows under gentle handling but solidifies under impact. It can be rolled into a ball that melts in your palm. On a vibrating speaker, it forms dramatic standing wave patterns.

Limpeza

Let oobleck dry and scrape off surfaces. Do NOT wash down drains. Dispose of dried oobleck in trash. Wipe surfaces with damp cloth.

Detalhes

Categoria
Classroom Demonstrations
Dificuldade
Beginner (Middle School)
Duração
20 min
Custo estimado
$3,00
Passos
6
Materiais
3

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Frequently Asked Questions

What is the objective of Fluido Não Newtoniano: Oobleck?
Criar e explorar um fluido não newtoniano que se comporta tanto como sólido quanto como líquido dependendo da força aplicada.
How difficult is Fluido Não Newtoniano: Oobleck?
This experiment is rated as Beginner (Middle School). It takes approximately 20 minutes to complete.
What safety precautions are needed for Fluido Não Newtoniano: Oobleck?
Key safety precautions include: Cornstarch is slippery when wet — clean up spills immediately; Do not pour oobleck down the drain — it will clog pipes; Non-toxic but not for consumption.
What materials are needed for Fluido Não Newtoniano: Oobleck?
The main materials required are: Cornstarch, Water, Food coloring.
What results should I expect from Fluido Não Newtoniano: Oobleck?
The oobleck flows under gentle handling but solidifies under impact. It can be rolled into a ball that melts in your palm. On a vibrating speaker, it forms dramatic standing wave patterns.