Move Like an Ancient Egyptian

Patent License for personal or one-class use only --© 2011 Particular Concepts LLC For more information go to: http://particularconcepts.com Move Like An Ancient Egyptian? By Elsie Spry Motion Forces are Everywhere: • Pouring a drink into your glass, you use the motion force of gravity. • Closing a door against rain, you use the motion force of your arm. • Riding in a car, the engine uses the motion force of a small gas explosion. You use motion forces every day. Ancient Egyptians used forces to move things too. Thousands of years ago, they moved huge obelisks many miles to stand in temples. Most people think they used lots of humans pulling on ropes. But what if they knew something we don’t? What if they used another kind of force? Dr. William Spry is a physicist (someone who studies forces --and my Dad) who thinks the Ancient Egyptians used something they had a lot of: dry sand. How can you use sand to move things? By using the gravity “stored” in the sand. And by learning some new vocabulary! Solid Particulate Sand is a solid particulate. A solid particulate is a solid, separate item that --when you have a whole bunch of them --you can pile. Other examples of particulate are rice, gravel, dirt, leaves, oatmeal, and even frosted flakes. Angle-of-Repose When you pile a particulate, it stops to form a hill at its special slope, called an angle-of-repose (sand has a different angle-of-repose than frosted flakes). When you add more to the pile, the particulate flows down the sides like a liquid. When it reaches the same slope as before --it stops! Bigger pile, but same angle-of-repose. Gravity Gravity is the constant downward force that pulls everything on the earth’s surface toward the center of the earth. It pulls the particulate too! Rankine Force When a pile of sand exceeds its angle-of-repose, the force of gravity turns all the separate grains in the pile --flowing down the sides --until the pile reaches its special angle-of-repose and stops. The grains --or particulates --keep on turning and moving as you add more. With each downward “turn” or “tumble”, the force of gravity changes from downward to sideways. William Patent License for personal or one-class use only --© 2011 Particular Concepts LLC McQuorn Rankine identified this force more than 150 years ago. Physicists and Civil Engineers call it the Rankine Force. Until recently, you would only hold the Rankine Force back. Civil Engineers worry about it when cutting through a hill. They don’t want the hill tumbling down over a road or building. So, they build retaining walls to stop the Rankine Force. But you can also use the Rankine force to move things. Dr. Spry calls it the Rankine Motive Application (I call it the Spry Go!). __________________________________________________________ The Move Like An Ancient Egyptian? activity shows how to move a cup (with rice instead of sand), using the Rankine Motive Application (or Spry Go!). So...Pretend you are an Ancient Egyptian Engineer moving a huge obelisk to the temple --thousands of years ago! Patent License for personal or one-class use only --© 2011 Particular Concepts LLC Move Like An Ancient Egyptian? Spry Go! Activity What to Have ___ About one (1) pint of water ___ A watertight bowl ___ Two (2) pitchers (One to pour water; one to pour rice) ___ Paper or other light, disposable cup ___ One (1) gallon of dry rice (or more) ___ Jelly roll pan (a cookie sheet with raised edges) ___ Block, book or other 1 to 2 inch object to support one end of the pan ___ A cup or scoop to help return the rice to the pitcher (hands work too) ___ Broom and dustpan (or canister vacuum) to help clean up What to Do 1. Ask the following questions questions; test, and circl ircl ircle your answer nswer nswer: ? Can you pour water? Pour water into the bowl Yes/No ? Can you pour rice? Pour rice on the jellyroll pan Yes/No ? Does water make a pile? Pour water in the bowl again Yes/No ? Does rice make a pile? Pour rice on the pan again Yes/No 2. Clear away the water, and put the rice back into a DRY pitcher. Patent License for personal or one-class use only --© 2011 Particular Concepts LLC 3. Set up the jellyroll pan, cup, book -- or block or other -- as shown: 4. Pour rice behind the cup, moving the cup up the jelly roll pan: 5. Describe what you did: __________________________________________________________________ __________________________________________________________________ 6. Describe what worked and/or what didn’t work: (For example, how does pouring the rice in front of the cup work?) __________________________________________________________________ __________________________________________________________________ 7. Describe how YOU would use this force in another way: __________________________________________________________________ __________________________________________________________________ Patent License for personal or one-class use only --© 2011 Particular Concepts LLC Move Like An Ancient Egyptian? NATIONAL SCIENCE STANDARDS PK to 12 Unifying Concepts: Evidence, Models, and Explanation Science as Inquiry: Understanding of Scientific Concepts Physical Science: Motions and Forces Science and Technology: Abilities of Technological Design History and Nature of Science: Science as a Human Endeavor Nature of Science Nature of Scientific Knowledge History of Science Historical Perspectives