Walking on custard
In this activity, students watch the Brainiac video Jon Tickle walks on custard on YouTube to learn more about non-Newtonian fluids at work. The activity includes a number of strategies to deepen student interaction with video content.
Oobleck
Oobleck – a cornflour and water mixture named after a substance in a Dr Seuss book – initially behaves like a liquid or a jelly. However, when you squeeze it in your hand, it behaves like a solid for a short time. It becomes more viscous when agitated or compressed and belongs to a subset of non-Newtonian fluids called dilatants. When a force is applied to a dilatant, its viscosity increases.
By the end of this activity, students should be able to:
discuss the differences between Newtonian fluids (‘normal liquids’) and non-Newtonian fluids
explain the scientific meanings of stress and strain as they relate to fluids
discuss how non-Newtonian fluids change their viscosity or flow behaviour under stress
explain why Jon Tickle is able to walk on custard but not on water.
Download the Word file (see link below) for:
background information for teachers
teacher instructions
student instructions.
