Author: Maddie Van Beek

Today we are going to learn more about simple machines. Last week we focused on the lever. You learned about levers by creating a ping-pong ball launcher and testing different kinds and positions of fulcrums. 


If you missed it, check it out here: http://www.discoveryexpresskids.com/blog/levers-and-launchers


Reminder, a lever is: A simple machine that contains a beam and a fulcrum. 
A fulcrum is: The point at which the beam of the lever rests and pivots. 


Examples: A seesaw, scissors, chopsticks. Can you think of more? 


This week, we are going to test out an inclined plane. Before we learn about inclined planes, let’s review what a simple machine is. 


A machine is...
-something that makes work easier for us. 


Work can be defined as...
-the force acting on an object in the direction of motion. 
-force times distance. (Work = Force x Distance)


Work sometimes is too great for humans to complete on their own, so we use machines to help us with that work.


A simple machine could be any of the following: 

• Wheel and axle
• Lever
• Inclined plane
• Pulley
• Screw
• Wedge

Read more about the six simple machines that make work easier at http://www.livescience.com/49106-simple-machines.html.


Check out this video for a quick explanation of what an inclined plane does for us: 

Follow-up questions:
1. What is another word for an inclined plane?
2. How does an inclined plane make work easier for us? 
3. When would an inclined plane be useful?
4. What is mechanical advantage? 


Can you think of an inclined plane that you’ve seen in real life? Here’s a few examples: ​

Author: Maddie Van Beek

Today, we are exploring the concepts of levers and fulcrums. You are going to create a simple machine that contains both a lever and a fulcrum--a ping-pong ball launcher! Before we get started, you need to know a little bit about what a lever is and what a fulcrum is.


First of all, what is a simple machine?


Think about what a machine does. There are so many different machines out there, but the main purpose behind machines is that they make life easier for people. Simple machines make work (the force acting on an object in the direction of motion) easier for humans to complete.


A simple machine could be any of the following:


* Wheel and axle
* Lever
* Inclined plane
* Pulley
* Screw
* Wedge


Read more about the six simple machines that make work easier (http://www.livescience.com/49106-simple-machines.html).


The simple machine you’re creating today is a lever.


A lever contains both a beam and a fulcrum. The fulcrum is the pivot of the lever. Think about levers in your everyday life. When have you seen a lever? One example is a seesaw... the bench that the two people sit on is the beam, while the center piece holding the beam in place is the fulcrum.

Fulcrum: The point at which the lever rests, is supported, and pivots.


Lever: A bar or beam resting on a pivot. Pressure (force) is applied to one end to help move an object (load) on the other end.


Check out the diagram of a lever below. You can see the beam resting over a pivot, which is the fulcrum. When you think of the ping-pong ball launcher you are about to create, the force will be you pushing down on the lever, and the load will be the ping-pong ball.

Now that you know a little bit about levers, you can get started on creating your own!


YOU WILL NEED:
* Plastic cup
* Ping-pong balls
* Wooden yardstick
* Tape
* Variety of fulcrums (thick book, shoe box, coffee can, log, etc.)


Here’s what to do!
1. Tape a plastic cup to one end of the wooden yardstick. Make sure you use lots of tape so the cup stays put! Your finished product should look like the shape below. The base of the cup is taped down, and the mouth of the cup is facing up. This is your ping-pong launcher!

2. Select your first fulcrum.
3. Set your your ping-pong launcher over the top of the fulcrum. The launcher should lean to the side over the fulcrum like the shape below.

4. Place the ping-pong in the plastic cup on the lower end of the launcher. Make a prediction, how far do you think the ping-pong ball will fly?
5. Quickly press down on the top end of the launcher to send the ball flying! Use a tape measure to check how far the ping-pong ball traveled. Repeat this five times and record your results each time. After the fifth launch, find the average launch distance. Do this by following the formula below.


Launch 1 + Launch 2 + Launch 3 + Launch 4 + Launch 5 = Total launch distance


Total launch distance / Number of launches


Total / 5 = Average Launch distance


6. How might changing the position of the fulcrum change the launch distance? Try moving the fulcrum closer to the launch cup.

Repeat step 5. What did you notice about the launch distance?


7. Try moving the fulcrum further away from the launch cup. Repeat step 5. What happened this time?

8. Record your conclusion. Which position launched the ball the furthest?


Extension: Now that you know which position works best, try using different fulcrums! Do different sizes or shapes affect the launch distance? Repeat the activity with at least two other fulcrums to determine which works best.


References:
http://buggyandbuddy.com/science-kids-launching-ping-pong-ball-snowmen/
http://www.livescience.com/49106-simple-machines.html

Author: Maddie Van Beek

​Today, we are going to perform some experiments on some Valentine's candy and make a DIY crystal Valentine gift for someone!


Candy Hearts Experiment
In this experiment, you will determine whether candy hearts react with baking soda or vinegar. You are looking for a chemical reaction.


A chemical reaction...
* Occurs between two or more atoms or molecules
* Causes bonds between atoms to break
* Forms new bonds
* Creates new molecules


Basically, two substances interact to create a new form or substance.


Read this link for more information on chemical reactions:

Now that you know a little bit about chemical reactions, let’s move on to our experiment!


YOU WILL NEED:
* Candy hearts (Sweethearts brand)
* Vinegar
* Baking soda
* Water
* Two bowls
* Glass
* Measuring cups


Here's what to do!
1. Place a few candy hearts in each bowl.
2. Add 1 cup water and 1 tablespoon baking soda to your glass. Stir until the baking soda dissolves.
3. Pour 1/2 cup vinegar into the first bowl. Observe what happens.
4. Pour 1/2 cup baking soda water into the second bowl. Observe what happens.
5. Which addition caused a chemical reaction, the baking soda water or the vinegar? Why do you think this is? Write down your thoughts.
So, you noticed that your candy hearts react with the baking soda water and not with the vinegar. What does that tell you? What else reacts with baking soda? Think back to other science experiments you may have done in the past. For more info, take a look at this blog we posted back in 2014:

Now that you know candy hearts react with baking soda, you are going to figure out WHY they react with baking soda. What ingredient in a candy heart might be causing this reaction? Take a look at the ingredients on the back of your candy hearts package.
I found that candy hearts contain these ingredients:
* Sugar
* Corn syrup
* Dextrose
* Glycerine
* Artificial and natural flavors
* Gelatin
* Vegetable gums (tragacanth, xanthan, arabic)
* Citric acid
* Artificial colors (red 3, yellow 5, yellow 6, red 40, blue 1)
You are going to test each of these ingredients separately to see which one is causing the chemical reaction.


YOU WILL NEED:
* Muffin tin (or several small bowls)
* Baking soda
* Sugar
* Corn Syrup
* Lemon juice
* Glycerine
* Water
* Food coloring

Here's what to do!
1. Put one teaspoon of sugar in one muffin cup and label it “sugar.” Put one teaspoon of corn syrup in the second muffin cup and label it “corn syrup.” Continue this process with the lemon juice, glycerine, and food coloring.
2. Add 1/4 cup water to each ingredient. In the sixth muffin cup, add 1/4 cup plain water.
3. Stir each ingredient until it dissolves in the water.
4. Now you get to start testing!
5. Add a spoonful of baking soda to each muffin cup. What happens? Which one reacts?


You should have noticed that the muffin cup with the lemon juice produced fizzing bubbles! There’s your chemical reaction! Remember, lemon juice contains citric acid. The citric acid in the candy hearts is what caused them to react with the baking soda water in your first experiment. Baking soda is a base. When acids and bases are mixed together, they react. That reaction produces carbon dioxide gas. You saw that gas in the form of those fizzy bubbles.

Another acid-base reaction that you have probably seen before is between baking soda and vinegar. Mix them together for more fizzy fun!
Now that you've performed some experiments, you get to use your crafty skills to make a valentine decoration!


Crystal Heart
You are actually going to create a crystal decorative heart by first boiling borax and then letting it crystallize.

What is borax?

Borax (short for boric acid) is a white mineral that is often used for cleaning. In its natural form, it is actually a crystal. Large borax deposits are found in California and Turkey, but borax is also commonly found in Tibet, Romania, and Bolivia.
​
Borax crystal can be white or clear.  Below is an example of white borax:

Here's a little bit more about borax:

What is crystallization?

We've seen crystallization in action when we created crystal egg geodes or when we made our own rock candy.

You are going to create a borax solution by adding borax to boiling water. When you add borax to water, it will dissolve. If you keep adding borax, eventually there will be a point that no more will dissolve. At this point, your borax solution is saturated. If you keep adding borax, it will just sink to the bottom and the solution becomes supersaturated. This means that the liquid in the solution contains more solute (borax) than it can hold. A supersaturated solution is unstable, so it produces a precipitate. A precipitate is a solid that is produced from a solution. In this case, the precipitate is your borax crystal.


YOU WILL NEED:
* Borax (Find it in the same area as the detergents in your local grocery store)
* Food coloring
* Pipe cleaner
* Water
* Saucepan
* Stove


Here's what to do!

​1. Boil water in a saucepan on the stove. (Make sure you ask an adult for help)
2. While you’re waiting for the water to boil, create a heart (or whatever shape you want) out of your pipe cleaner. When you’re finished creating your shape, place it in a glass jar.
3. Once the water boils, add borax. Stir until the borax dissolves. Continue adding borax until it will no longer dissolve. You’ll know your solution is supersaturated when the borax just sinks to the bottom. Remove the solution from the stove and add food coloring (optional).
4. Pour the borax solution into the glass jar. Make sure your pipe cleaner shape is completely submerged.
5. Leave the jar undisturbed for 24 hours.
6. Check back the next day. What happened?! Dump the borax solution down the drain and remove your crystal heart.


References
http://inspirationlaboratories.com/valentine-candy-science-candy-heart-reactions/
http://inspirationlaboratories.com/valentine-candy-science-candy-heart-ingredients-experiment/
http://fun-a-day.com/candy-heart-experiments-valentines-day/
http://chemistry.about.com/od/valentinesdaychemistry/a/Borax-Crystal-Heart.htm

Sometimes the weather doesn't behave the way you want it to. In Fargo this weekend, it was icy and sleeting. Yuck!
​
Today, we are going to do a few science activities that allow YOU to control the weather!
​
Fog in a jar
In this activity, you will see how cold air and warm air creates fog.

What exactly is fog? Fog is actually very similar to a cloud, except it's near the ground. Both fog and clouds are actually tiny droplets of water in the air. There are many different types of fog and ways that fog can form, but all kinds of fog form because of a temperature difference between the air and the ground.
​
Check out the link below to learn about some common types of fog:
https://weather.com/science/news/how-does-fog-form-20131010


Now that you know a little bit about fog and how it forms, you get to create your own!


YOU WILL NEED:
* Jar
* Strainer
* Ice
* Warm water

As you may know, tornadoes are known for their funnel shape and their power of destruction. Most tornadoes form from thunderstorms. Warm air and cool air meet, and sometimes a swirling mass is created and escalates into an even more violent storm. Another name for the shape of a tornado is a vortex. Vortexes also appear in black holes or whirlpools. You are going to create your own vortex today to simulate a tornado.


Check this link out to learn how more about tornadoes form:
http://eschooltoday.com/natural-disasters/tornadoes/how-do-tornadoes-form.html


YOU WILL NEED
* 2 Liter bottle
* Large pitcher
* Water
* Stopwatch

Here's what to do!

1. Fill the 2 liter bottle 3/4 full of water.

2. Your challenge is to identify which way water escapes the bottle the fastest--when it’s swirling like a tornado, or when it's allowed to just fall through without swirling.

3. Flip the bottle upside-down over the pitcher. What happens? Not much. You’ll see the water pass from the bottle to the pitcher. You might hear a kind of glugging noise as the water escapes the bottle.

4. Pour the water from the pitcher back into the bottle. This time, you are going to time how long it takes for the water to pass from the bottle to the pitcher, so get your stopwatch ready!

5. Flip the bottle and time how long it takes for the water to empty into the pitcher. Record your result, then pour the water back into the bottle.
​
6. Now, it's time to create a tornado! You’ll flip the bottle again, but this time swirl the bottle in a clock-wise motion until you see a tornado form. You should be able to see the vortex right in the middle of the bottle. Did the water seem to fall through quicker or slower this way? Try it again and time it! Which way was faster?


You may have noticed that water fell through to the bottom bottle much faster when it was swirling. This is because as the water falls from the top bottle to the bottom bottle, the air at the bottom needs to get to the top, to make room for that water. The vortex that you created by swirling the water creates a tunnel for the air to move to the top bottle at the same time that the water is moving to the bottom bottle. When you flip the bottles without swirling the water, there’s no pathway, so the water and air have to take turns falling through the neck of the bottle, hence the glug-glug noise.


Extension: Create a tornado-simulator that you can use over and over!

YOU WILL NEED
​
* Two 2 liter bottles
* Water
* Food coloring
* Super Glue
* Duct tape


1. Fill one 2 liter bottle 3/4 full of water.

2. Add food coloring of your choice. You could even add glitter or confetti!
​
3. Carefully line the mouth of the bottle with super glue. Place the mouth of the second 2 liter bottle on top of the mouth of the first 2 liter bottle and hold for 30 seconds. Leave the bottles alone while the glue dries for 20 minutes.

4. Tape around the necks of the bottles. Make sure to use a lot of tape so the bond is secure! It should look like this: 

5. Once your bottles are securely taped, try out your tornado! Flip the bottles upside-down and swirl them just like you did before to get the vortex going.


For another weather-related activity, check out our blog about air masses: http://discoveryexpress.weebly.com/blog/the-science-of-air-masses-what-happens-when-air-masses-collide




References:
http://www.universetoday.com/85349/how-does-fog-form/
http://www.funology.com/london-fog-anywhere-you-want-it/
https://weather.com/science/news/how-does-fog-form-20131010
https://www.stevespanglerscience.com/lab/experiments/tornado-in-a-bottle1/

Last week we did science for the sweet tooth. This week, we are using simple potatoes to create magic goop that’s fun to play with! The magic mud that you’ll be creating behaves similarly to the slime you concocted in an earlier post. If you missed this fun and messy experiment, check it out here: http://discoveryexpress.weebly.com/blog/two-times-the-slime-fun-with-polymers.


This weird slimy substance that you’re working with today is a non-newtonian fluid. Non-newtonian fluids behave very differently from normal liquids or solids. Instead, they sometimes behave like a liquid and sometimes behave like a solid. When you apply pressure to a non-newtonian fluid, it resists and behaves like a solid. As soon as you release the pressure, the fluid returns to liquid form.


For a real-life example of this odd behavior, check out this video of someone biking across a pool of corn starch!

Although many people have experienced creating non-newtonian goop with corn starch, the magic mud you’re creating today behaves in the same way. How will you create the same kind of substance with a potato? Potatoes actually contain starch. You will have to first remove the starch from the potatoes to create your magic mud.

​Here's a video example of what you will be doing:

YOU WILL NEED:
* Bag of potatoes
* Water
* Food processor (optional)
* Knife (if food processor is not an option)
* Saucepan
* Kettle
* Strainer
* Jar


Here’s what to do!


1. Find an adult to help you with this activity! You may need to use a knife and you will use the stove, so make sure to be work carefully!
2. Wash a bag of potatoes in the sink.
3. Put your potatoes in the food processor and grind them into small pieces, or have an adult help you chop the potatoes into tiny pieces with a knife.
4. Dump the chopped-up potatoes into a mixing bowl.
5. Heat about 6 cups of hot water in the microwave or on the stove.
6. Carefully dump the hot water over the potato bits in the mixing bowl.
7. Stir the potatoes for a few minutes. What do you notice happening as you stir? The water actually changes color.
8. After about two minutes, place a strainer over an empty clear mixing bowl. Pour the potato water through the strainer to separate the liquid from the potato bits. Pay close attention to the liquid in the mixing bowl! What do you see happening? After 10 minutes, the liquid separates into two layers. The bottom of the bowl is white, while the reddish-brown liquid stays on the top. The white stuff you’ve removed from the potatoes is the potato starch. The starch is the necessary ingredient in making your non-Newtonian magic mud.
9. When this separation has happened, dump the top layer of liquid into the dirty mixing bowl. You should be left with just some white goop. The white goop looks a little dirty, so we are going to separate it even further.
10. Stir in about a cup of fresh water with the goop and pour it into a clear jar. Shake it up for 30 seconds and then let the jar sit for 10 minutes. You should notice that, once again, the liquid separates into two layers. The impurities stay on the top while the white goop sinks to the bottom.
11. Dump out the top layer of liquid. This should remove the impurities. You’re left with a milky-white substance. What does this substance feel like? Play with it! What do you notice about it? How does it act when you apply pressure? Try to roll it into a ball. What happens when you stop rolling? You’ll notice that when you stir it or roll it, the substance seems more firm, but when you stop applying pressure, it looks more like a liquid.


Extension:
Now that you’ve created your magic mud, go one step further and make it glow!


YOU WILL NEED:
* Fork
* Tonic water
* Black light


Here’s what to do!


1. Leave your magic mud in the jar for at least 24 hours. It will harden from a goopy slime into a solid.
2. Before you recreate your magic mud, take a look at your tonic water under a black light. Turn the black light on and the lights in the room off. What do you notice about the tonic water? It should be a glowing blue! The reason the tonic water is fluorescent under black lights is because of the ingredient quinine. (Don’t worry, the quinine in the tonic water is totally safe and non-toxic.)

Fluorescent objects absorb ultraviolet light that we can’t see, but they emit light than we can see. Read more here: http://www.scientificamerican.com/article/shining-science-explore-glow-in-the-dark-water/

The quinine in tonic water causes it to glow under a black light, so anything you mix with tonic water will also fluoresce! We are going to use tonic water to make your magic mud fluorescent. Turn the lights back on and let’s get going!

3. Use a fork to break up the solidified magic mud. It will easily crumble into a white powder.
4. Carefully add tonic water into the white powder. Add small amounts at a time and stir until the powder returns to its former goopy consistency.
5. Play with your new goop. What do you notice? It should behave exactly as it did before you let it dry. Here’s the big difference: When you turn on a black light, your magic mud will now eerily glow blue! For more fluorescent fun: Remember when we used tonic water to concoct glowing beverages for Halloween? Check it out here: http://discoveryexpress.weebly.com/blog/halloween-science).


References:
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