Floating Japanese Penny

Let's take a look!

Watch the video on YouTube.

What kind of experiment is this?

Experimental procedure and explanation:

• You can float a Japanese penny, which is made of aluminum, on water.
• The reason is often explained as “surface tension” but buoyancy also has an effect. The ratio between surface tension and buoyancy is about 1.7:1.

[Keywords]	surface tension, buoyancy
[Reference]	“The Wonders of Flow” Japan Society of Mechanical Engineering, Kodansha Blue Backs pp. 42-47.