Read an Excerpt
Curious Minds
40 Hands-on Activities to Inspire a Love of Learning
By Ty Kolstedt, Azeem Z. Vasi Chicago Review Press Incorporated
Copyright © 2016 Ty Kolstedt and Dr. Azeem Z. Vasi
All rights reserved.
ISBN: 978-1-61373-153-6
CHAPTER 1
PART I
PHYSICS & MATH
SHOOT! MINE DIDN'T OPEN: THE SCIENCE OF PARACHUTES
Content Focus: Physics
Primary Skills Focus: Design and Model
Mission Objective: Jump into the basics of air resistance with a brief history of parachute design. Then, construct multiple styles of parachutes and test the merits of each design.
If you take a feather and pea and drop them from the same height, which one falls faster? The pea, right? One of the reasons this is the case is air resistance. In this mission you will become an expert in air resistance and design your own parachutes.
The idea of the parachute has been around for hundreds of years. While some say the ancient Chinese used a parachute-like device to jump from heights and perform acrobatics, Leonardo Da Vinci created the first known drawings of a modern-style parachute in 1483. His design was a four-sided pyramid made of wood and canvas. In June 2006 Adrian Nicholas glided to the ground safely using a parachute based on a sketch Da Vinci did of his parachute design. The builders of Nicholas's parachute only used materials that would have been available to Da Vinci during his life. Isn't that cool?
Parachutes work because of air resistance. When a parachute is deployed (opened) there is drag, or air resistance, that pushes up the parachute and slows down the jumper. It is the parachute's light weight and large surface area that harness the power of air resistance. It's all about air molecules. A human without a parachute would fall fast because he or she would push through the air molecules very easily (like the pea). Air resistance is generated as the parachute runs into air molecules when hurling toward the Earth (like the feather). The force of all these air molecules pushing against the parachute slows its descent (drop).
After Da Vinci made his initial drawings in the 15th century, progress on the idea slowed and the parachute did not play a significant role until the early 20th century (or 1900s). Parachutes had lost the rigid frame and were now made of either nylon or silk. From the early 1900s to the 1960s parachutes had a circular design as shown here:
While these parachutes did get the traveler to the ground safely, the jumper didn't have the ability to steer them. The parafoil parachute design created in the 1960s included that improvement. The parafoil design is a rectangular-shaped wing capable of being steered to where its passenger wants to land. Did you know that some competition jumpers can land within inches of a target?
Learning the Lingo
air molecules: The tiny, microscopic building blocks of nitrogen, oxygen, and carbon dioxide that make up the atmosphere around our planet.
descent: The movement down, or lower. In this case it refers to the parachute jumper's fall to the ground.
drag: The air resistance that is created by an object falling. Typically, items with less mass and more surface area create more drag and fall slower.
parafoil: A parachute design developed in the 1960s that gave the jumper greater control and mobility. This is due to the rectangular design and air "pockets" that jumpers can steer with handles, or toggles. This design is still used today.
Materials
• 3 heavy trash bags
• 1 roll of tape
• 1 roll of string
• 50–75 Popsicle sticks
• Wood glue
• 3 plastic shopping bags
• 1 roll of paper towels
• 3 eggs
Plan of Attack
We know the parafoil parachute provides the jumper with the most mobility (the ability to steer), but which design (Da Vinci's, a complete circle, or the parafoil) can land a jumper softest, and therefore safest?
1. Hypothesize (make your best educated guess) as to which design is safest. Why do you think that?
2. Use the trash bags, tape, string, and Popsicle sticks and glue to create three parachutes: a Da Vinci, a circular, and a parafoil. You will use the sticks and glue for the Da Vinci design but for the most part try to use the same amount of material for each parachute. You will want to reinforce the holes in the parachute corners where you tie your strings with small pieces of duct tape. The drag will put significant pressure on the bag and it may tear without reinforcement.
3. Use the plastic shopping bags to make a cradle for an egg to hang under the parachutes. Tie the parachute strings to the plastic shopping bag handle. At the bottom of the bag, use paper towels to cushion the egg.
4. Next, have an adult drop each egg/parachute combination. Try to drop them from an upstairs window, balcony, stairwell, or ladder. Your goal is to drop them from as high as possible to give the parachute the greatest opportunity to "catch" enough air resistance to guide the egg down.
5. What happened? Was your hypothesis correct?
6. Try putting a small hole in the middle of each parachute and see if that helps balance and smooth out the descent. Why might that help?
7. Try experimenting with different-sized parachutes of the same design. What is the relationship between parachute size and speed of descent?
Take It to the Max!
While the goal of the parachute is to slow the jumper down and allow him or her to land where he or she wants, what if you want to feel what it is like to fly? There are action sports enthusiasts who wear a special suit called a wingsuit. This is a suit with fabric connecting the arms and legs (think of a flying squirrel). Do some investigating to figure out how these suits work and how these daredevils are actually riding the wind!
IS A PENNY SAVED REALLY A PENNY EARNED? LESSONS IN INVESTING
Content Area: Math
Primary Skills Focus: Interpreting Data
Mission Objective: Explore the world of investing and get an introduction to the stock market. "Buy" stock in a company of your choosing and track your "money" over time.
You are about to become an investment wizard as you learn about the stock market and the banking system. Have you ever wondered how the stock market works? Can someone make money by just putting that money in the bank? Can you lose money when you invest it?
It is never too early to learn about savings and investments, and this is your chance to become an investment expert. Next stop, Wall Street!
Learning the Lingo
compound interest: When you have interest added to principal and that new total gains interest as well. Confused yet? Check this out:
Your Savings Account
Principal Amount $1,000
Interest Per Year 10% (10% of 1,000 is $100)
Amount in Your Account After 1 Year: $1,100 (1,000 + 100)
Interest for 2nd Year 10% (10% of 1,100 is $110)
Amount in Your Account After 2 Years: $1,210 (1,100 + 110)
You started with $1,000, and after two years of compound interest you have $1,210.
interest: An excess or bonus on loaned or invested money. Example: if you put money in a savings account the bank actually gives you extra money just for keeping the money in that account. Interest is usually described as a percentage.
principal: The original amount of money described when investing, as in the amount of loan or investment that you start out with. If someone loans you $1,000, that is the principal amount.
shares: A way to represent part ownership in a corporation or other investment. One share is one unit of ownership of whatever you are investing in.
stocks: Certificates that represent the percentage of a company that you own by investing money in that company. These stocks can be bought and sold on something called the stock market. Some people also call these shares.
Materials
• Calculator
• Scrap paper
• A newspaper from the last seven days with a stock market section (found in the business or financial section) or access to the Internet and the page www.google.com/finance
Plan of Attack
Buying and selling stocks is one way to invest money. Stocks each have a unique "ticker symbol," which is a set of letters that represent that company. These ticker symbols help you track the price of stock in the company you have invested in.
Selected Companies and Their Ticker Symbols
Coca-Cola
KO
Google
GOOG
Wal-Mart
WMT
AT&T
T
Ford Motor Co. F
1. Studying the stock market information you found online or in the paper, find the prices for one share of each of these companies' stock.
2. What would explain the different costs of stock in each of these companies?
3. Pick one of the stocks from this list. Imagine you had $1,000 to invest in stock of your chosen company. How much stock could you buy? (Hint: divide your total amount of money ($1,000) by the price of your chosen stock.)
4. On the first day, write down the number of stock you could buy with your $1,000.
5. At the end of one week, imagine you sell all the shares of stock you bought. Look up the price of stock for your company on day seven and multiply that by the number of shares of stock you own (from step 4).
6. How much money did you end up with? Did you gain money or lose money?
7. Why would someone invest money in the stock market if you could lose it?
8. How much money would you have if you put your initial investment ($1,000) in a savings account that earned 5 percent interest per year after one year? What if you kept your principal and your yearly interest in the account every year; how much would you have after 10 years?
As you can see above, investing can be risky. If you sell a stock for a lower price than you paid for it, you can end up losing money. But, if the company does well you can make money just by owning that small piece of it.
Over the long term, investing your money in an account that pays interest lets you take advantage of compound interest that helps your money grow. After doing these exercises you can see how by putting money in a savings account you can be making money from the compound interest.
So get to it and start investing and saving now!
Take It to the Max!
What are dividends on a company's stock? Do all companies that have stock give out dividends? If you use your dividends to buy more stock, does compound interest help you make more money? Learn about the money-making power of dividends!
Answers to question 8: $1,050.00 and $1,628.89
SPANNING THE AGES: THE PHYSICS OF BRIDGES
Content Focus: Physics
Primary Skills Focus: Design and Model
Mission Objective: Discover the principles of compression, tension, and bridge construction. Construct multiple bridges using different styles and techniques to test your newfound knowledge.
What are some structures that were built thousands of years ago and still exist today? You were right if you guessed the Great Wall of China or the Egyptian pyramids. But did you also know that there are other structures that have stood the test of time? In this mission you will take on the role of engineer and learn all about these sturdy marvels: bridges. How do bridges work? What kind of engineering advances made some bridges strong, even thousands of years after they were originally built?
Any bridge that spans a distance has distinct forces acting upon it: compression and tension. Compression refers to the forces acting upon that bridge that push in, or compress, when weight is applied to the bridge. Tension refers to forces that try to stretch, or lengthen out, the bridge when weight is put on the bridge.
This activity will focus on three types of bridges: beam, truss, and arch.
A beam bridge is the most basic type. It consists of a horizontal beam supported by two vertical piers (or abutments). There is a lot of tension and compression acting upon this bridge so the materials that make up the bridge must be very strong. The longer the beam bridge, the weaker it becomes. You rarely see a beam bridge over 250 feet long.
A truss bridge is a more complicated type of bridge made out of interconnected triangles to increase the strength of the bridge. The trusses transfer the compression and tension from one point over the entire span of the bridge.
In a truss bridge the load (the compression and tension) is not just on one beam (like the beam bridge) but is shared between the top beam, bottom beam, and supporting triangles. Because the beams and triangles are connected, when the weight of the load is applied to the bridge, the weight burden is spread out and the entire bridge helps support the load.
An arch bridge is a semi-circle connected to supports (or abutments) on each side. This can be a very strong bridge because the compression is pushed outward toward the abutments so the beam does not have to support the whole load of the bridge.
Learning the Lingo
abutments: The foundation points on each side of a bridge that support its weight.
compression: The act of pressing or squeezing together. This happens on every bridge when weight is applied.
span: The portion of the bridge between its abutments, or supports.
tension: The act of stretching or pulling apart. This happens on every bridge when weight is applied.
truss: A rigid triangular framework used to increase the strength of a bridge by dividing the tension and compression among multiple supports.
Materials
• 2 chairs
• 500+ popsicle sticks (available at craft or hobby supply stores)
• Wood glue
• 5–10 spring-tight binder clips or clothespins
• String
• Bucket of water
Plan of Attack
There are a couple different ways to do this activity. If you are alone, take option 1. If you are doing this activity with someone, take option 2. First, hypothesize on which bridge type (beam, truss, or arch) will hold the most weight. Why?
OPTION 1
Build all three types of bridges and test out which one will hold the most weight. Note: You may want to do this activity outside as the floor may get wet.
1. First take your chairs, put the seat sections facing each other, and separate them about one foot apart. This will be how far your bridges need to span.
2. Next, build all three types of bridges using the popsicle sticks and glue. Use the binder clips to hold the sticks together while the glue is drying. Be creative with this and have fun. Try to build the strongest beam, truss, and arch bridges you can. For the arch bridges you may have to bend (or break) the popsicle sticks and glue them back together to form the arch.
3. To test out the strength of each, hang the bucket beneath each bridge as it spans the chairs. Add water, one cup at a time, until each bridge fails. The bridge that can hold the most water wins.
OPTION 2
In this option, you and a partner compete to see who can build the stronger bridge. You may choose to build any of the bridges (beam, truss, or arch) depending on which you feel you can build to be the strongest. Follow the same steps listed in Option 1. Whoever builds the bridge that can hold the most water wins.
(Continues...)
Excerpted from Curious Minds by Ty Kolstedt, Azeem Z. Vasi. Copyright © 2016 Ty Kolstedt and Dr. Azeem Z. Vasi. Excerpted by permission of Chicago Review Press Incorporated.
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