Saturday, June 11, 2016

// // Leave a Comment

How Sharks Float Experiment: Part 1 (of 2)

Did you know a whale shark can weigh more than an elephant?!  How can an animal that weighs thousands of pounds float through the ocean?  This experiment shows a big part of that answer!

Actually, some sharks do sink!  White-tipped reef sharks, and others, will rest on the bottom of the ocean and still breathe by sucking water across their gills as they rest.  All sharks will sink if they stop moving.  Some sharks, like the great white, can only breathe while they are moving!  So, how do they manage to float?!

We did two experiments to help learn about three main things that contribute to sharks floating and then do an experiment that demonstrates how the fin shape helps. The second experiment is HERE!

Three things that help sharks float are:

1- Cartilege Skeleton
2- Fin Shape
3- Oily Liver

1- Sharks' cartilege skeletons weigh a lot less than bones!  The lighter weight makes floating easier, but it isn't the whole answer!

2- Sharks' fin shape is amazing!  Just like an airplane wing creates lift by forcing air over the top faster than under the wing, a shark fin creates lift by forcing water over the top of the fin faster than under it.  The faster moving water is less dense (Bernoulli's Principle) and creates an upward force! By itself, this would not be enough force to lift up the entire shark, but combined with the light skeleton and the boyant liver, it is enough to make the shark float as it swims!

Try the experiment below to demonstrate the lift that low pressure can create!

Fun Fact: Velvet belly lantern sharks have glowing spots on their bodies!

3- Sharks' oily liver is the third key in how sharks float!  Oil will float on water because it is less dense.  HERE is a super fun experiment demonstrating this!  You can also check out this fish experiment and this penguin experiment for more fun with density, oil, and water!

Shark Fin Experiment:
Simple Supplies:

* tissue paper
* you!

Easy How To:

1- Hold one end of the tissue right underneath your mouth.  The other end will hang down by your chin.  Blow across it as hard as you can!

2- You are creating a low-pressure zone as the air in front of your mouth moves faster than the air down by your chin.  This creates a lift force that will move the tissue up so it is "hanging" straight out!

Do you love sharks?  Grab my {FREE} I Can Count to 10 With Sharks page and come back next week for another fun experiment with sharks and floating!!

My Science/STEM Saturday friends have some more great experiments going on this weekend too!  Check them out:

DIY Solar Oven Smores | Simple Summer Science from Lemon Lime Adventures
Frozen Fizzing Stars from Little Bins for lIttle Hands

And if you're looking for some fun summer science, browse our collection of more than 150 science experiments and activities!!

Amazon Affiliate Links:

Happy Educating,

I may share at any of these parties!

Never miss another post again!  Sign up for our weekly updates newsletter and get links to all our posts once a week in your inbox!  Sign up here!!