My guest post on Musings of a Mathematical Mom

# physics for kids

# Sink or swim

Sink or swim – a topic as old as our civilization. Everything about it is well known since Archimedes.

https://www.youtube.com/watch?v=0v86Yk14rf8

What can be added to a lesson on this subject to make it interesting and unusual? I decided on everyday vegetables and fruit. Carrots? Sink. Radishes? Sink. Onions? Swim. Apples? Swim. Lemons? Swim.

Ok, let’s peel this lemon.

Now it sinks! Why? Let your kids explain it.

Side note: a peeled lemon always sinks. If you try the same experiment with an orange or tangerine, the result is unpredictable and depends on the variety, size etc of the orange. If you want predictable results, use a lemon.