Sink or Float?

Introduction

Hello fellow scientists!!!

I have a question for you! Have you ever noticed in stories or movies about pirates that the boat stays on top of the water, but the treasure chest is on the ocean floor? Why is that?

In this WebQuest, it will be your job to find out why certain objects will fall through the water to the bottom and why other objects stay afloat on the surface.

Task

Let's begin by watching a video clip that explains why it is that certain objects float on top of the water and other objects will sink to the bottom.

[video:https://www.youtube.com/watch?v=eQuW8G2QV_Q]

After this video, we are going to try our own experiment with different objects! At the end of the activity, you will have a chart of which objects sank and which did float, as well as the ability to explain to your friends why you observed what you did.

Process

Let's try it!

I will be handing out a work sheet that you will be recording your observations on. I will also give each group a bucket of water and 4 different objects. As a group, you will make a prediction about which objects will sink and which will float. After you have done that, you will take turns putting the objects into the water to see if your predictions were correct!

The following links provide further explanation and activities about the sceince behind this experiment:

https://jr.brainpop.com/science/forces/sinkorfloat/preview.weml

https://www.brainpop.com/science/motionsforcesandtime/buoyancy/ (video)

http://www.pbslearningmedia.org/search/?q=sink+or+float&order=&selected…

Evaluation

Great job working together during the activity!!!

Now let's take a short quiz to see if you can pick out which objects will sink and which ones will float. Pull out you science notebook and write the numbers 1 through 10.

In each line, write "sink" or "float" and one or two words that explains why you chose your answer (example: light weight, empty space).

1. A raft on a big river

2. A big tree in the ocean

3. Your mother's phone in the toilet

4. A remote control boat on the lake

5. A penny in a wishing well

6. You in a swimming pool while you lay on your back

7. A float toy in the pool

8. A boat anchor

9. An empty soda can

10. A bowling ball

Now, let's get back into your groups and discuss your answers. I will walk about and talk to each table to see how you did.

Conclusion

Everyone did an amazing job!!

Now that we have learned what characteristics make objects sink and float, I challange you to explain what you learned to your family. Remeber, this includes an object's weight and size, the size of the body of water that it is being placed into, whether or not the object is hollow and the object's density.