A Low-Cost Teapot Effect Experiment for Introductory Physics

TL;DR

This paper introduces a simple, low-cost experiment using 3D-printed cups and basic materials to demonstrate the teapot effect, making it accessible for introductory physics education and illustrating fluid dynamics concepts.

Contribution

It presents an accessible, hands-on laboratory activity that visually demonstrates the teapot effect and related fluid phenomena for educational purposes.

Findings

Students can measure run-off length to analyze flow behavior.

The experiment effectively illustrates the influence of velocity and surface wettability.

It provides a pedagogically effective way to connect everyday observations with fluid physics.

Abstract

The teapot effect refers to the tendency of a poured liquid to cling to the lip of a container and run down the outside. It is a familiar but physically rich example of flow separation. We present a low-cost experiment for introductory physics laboratories that uses 3D-printed cups, a simple flow regulator, and basic surface treatments to explore this phenomenon in a classroom setting. Students measure the run-off length along the outer wall as an accessible indicator of sticking versus separation and use it to compare the effects of flow velocity and surface wettability. Rather than attempting a full quantitative test of research-level models, the activity is designed to illustrate the inertial-capillary picture of the teapot effect in a form that is experimentally straightforward and pedagogically effective. The experiment connects a familiar everyday observation to fluid inertia, wetting, and interfacial forces in a form that is well suited to introductory instruction.