Elementary Challenge 2: Float On
Density and buoyancy are important ideas that engineers need to know about. In this challenge you will learn about the density of different liquids, and then apply what you know to the concept of buoyancy, or how density affects an objects ability to float.
Supplies needed:
A glass of water filled with 1 cup of water
1/2 cup of cooking oil
1 Food Coloring
2 Alka Seltzer tablets OR some table salt OR a mix of vinegar and baking soda
1 piece of aluminum foil
a bowl of water or a sink
some rocks or coins
Let's Learn About: Density
Density helps us measure how many parts and pieces make up an object of a certain size. It describes how much “stuff” is in an object as compared to how big it is.
When finding density, we divide mass (how much matter is in an object) by volume (the amount of space an object takes up)
For example: If we have a snow globe with hundreds of little pieces of snow flowing around in it, it has a higher density than the same snow globe with three pieces of snow. This is because we have more snow per snow globe- more pieces per the same volume.
How Lava Lamps Work
Density, Mass, and Volume
Activity: Density and Lava Lamps
In this activity we’re going to study density by making a cool, short-lasting lava lamp.
En esta actividad vamos a estudiar la densidad haciendo una lámpara de lava fresca y de corta duración.
Supplies/Suministros:
1 Small Clear Plastic Water Bottle OR a glass of water filled with 1 cup of water
1/2 cup of cooking oil
1 Food Coloring
2 Alka Seltzer tablets OR some table salt OR a mix of vinegar and baking soda
Let's Learn About: Buoyancy
Remember what we learned about density? Density is how much “stuff” is in an object as compared to how big it is. Buoyancy helps us measure how much something will float up when placed in a fluid based on its density.
For example, let’s look at when we put ice in a glass of lemonade. The ice rises to the top of the glass right? This is because the ice is less dense or has less “stuff” throughout it than the lemonade does. How much the ice tends to rise in the lemonade is its buoyancy!
How do ships float?
Buoyancy with Bill Nye the Science Guy
STEM Challenge
Pretend you are an engineer. Your job is to design a boat that can hold as much weight as possible so that you can ship more boxes at once.
Supplies needed:
1 piece of aluminum foil
a bowl of water or a sink
some rocks or coins
In this STEM challenge, your task is to make a boat out of aluminum foil. After you've done that, you'll see how many coins can fit on your boat. Your goal is to get as many coins as possible, because you are an engineer who wants to ship large quantities of boxes - or, very heavy boxes - across the ocean.
Something to consider - the shape of your boat. We aren't going to tell you how to build your boat, but we want you to use the Engineering Design Process to protouy test out what shape works best. The Engineering Design Process is:
Ask a question, Imagine a solution, Plan the solution, Create the solution, Test the solution, Improve understanding to better solve a problem.
