One of my goals with these science videos is to provide support to the homeschool community. After years of writing the Experiment of the Week, and presenting science shows for homeschool groups, I have been impressed with how strongly homeschool families are involved with hands-on science. I have also seen the need for a science curriculum that fulfills their educational needs. Starting with these videos, I hope to offer the homeschool community some of the science education support that they need, as well as a fun way to get students involved with scientific discovery.
I also try to use activities that involve common items. Most homeschoolers don't have access to test tubes, flasks, chemicals, microscopes and other scientific equipment. In the future, I hope to be able to guide them to inexpensive sources for science equipment to enrich their science curriculum.
This week we will investigate the world of engineering. Instead of building a skyscraper, we will are going to build a bridge. Often, bridges can cost millions of dollars, but this one will only require a single dollar bill for its construction.
You will need:
- 2 drinking glasses
- a dollar bill
- 8 quarters or other coins
Place the two glasses on a flat surface, upside down. Place them far enough apart so that a dollar bill will reach from the center of one glass to the center of the other. Your task is to use the dollar bill to make a bridge from one glass to the other. Your bridge must be strong enough to support the weight of 8 quarters in its center. Take a moment and try it.
By placing the dollar flat on the glasses, it will not even support one quarter, much less all eight. How can we strengthen the dollar? There are a lot of people in the government that would like to know that.
To add strength to the paper, we will fold it. Start at the top of the bill and fold 1/4 of an inch of the paper towards the front of the bill and crease it. Then fold the next 1/4 of an inch towards the back of the bill. Keep making a fold each 1/4 inch, alternating between folding towards the frong and back, until you reach the bottom. When you finish, the folds in the bill should look something like this: VVVVVVV
Once you have all the folds, place the bill across the two glasses and gently place a quarter in the center. Your "bridge" holds it up. Add another quarter and another. You should be able to easily get the dollar bill to support all 8 quarters.
Folding the bill changes the lines of force in the paper. This folding is called corrugation and it is very useful for making things stronger. If you cut through a cardboard box, you will see the same shape. It is made up of a corrugated piece of paper, glued in between two flat pieces. Again the folding makes the paper stronger, forming a very strong box made of thin, light paper. Look around and see if you can find other things that use the same idea. Be sure to notice the metal siding on buildings, the construction of bridges and other structures that need to be very strong..
Have a wonder-filled week.
