September 5th Bernoulli Principle and Siphon Effect
If you missed today you should at least read through these notes and watch the videos. We did not collect anything today.
Einstein Whiteboard
Rube Goldbergs #1-10
Finish up all six siphon demonstrations (U shape hose, pressure metal cans, normal siphoning of pail of water, greedy cup, homemade greedy cup, toilet video)
Can two cans be drawn together without touching them or blowing air at them? Bernoulli says, "Yes!" Watch as the faster air causes a lower pressure between the cans.
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Another homemade siphon like the greedy cup (video tape it)
How does a siphon work? Pressure at the end of the higher tube higher than the pressure at the top of the hose so everything moves from high pressure to low pressure thus once you get it going (because of tensile strength of water) it continues flowing until empty or you change the pressure difference by raising the upper end out of the water. (Draw picture on smart board)
Side Note: Tensile strength is the maximum load that a material can support without fracture when being stretched, divided by the original cross-sectional area of the material.
Show how each of the siphon's work in each demo.
Side Note: Tensile strength is the maximum load that a material can support without fracture when being stretched, divided by the original cross-sectional area of the material.
Show how each of the siphon's work in each demo.
Video of how a toilet works.
Demo of vacuum cleaner blowing air out and holding a suspended ball off to the side.
How it works: The air over the top of the ball has to travel faster because it travels a greater distance in the same amount of time the air on the bottom traveling a shorter distance. The faster air on top of the ball causes a lower pressure and since objects move from higher pressure (bottom of the ball) to lower pressure (top of the ball) it gives the ball enough lift to overcome the force of gravity.
Video of Bernoulli Effect (explained)
Story of Roof blowing off home
One day while visiting my brother in Prairie du Chien we were in his basement talking when we heard a train like sound go by (strong wind blew by). Next my brother got a phone call asking if we were alright because they had just heard on their police scanner that his neighbors' roof was gone. We walked across the street and sure enough the roof was off the home next door and landed a full block away in another neighbors lawn. The lady in the house said she had crawled under her dining room table and after she heard the loud noise, she looked up and outside the table and could see stars. The high velocity wind lifted her roof off just like a paper from the top of a basket you are carrying flies up and onto the floor.
Penny activity: Lay a penny (any coin really) on the edge of your table and do a short quick blow with your mouth so your wind blows parallel to the pennies surface across the top. The penny will lift and go into a cup or onto your open hand if you do not have a cup. How many coins can you lift with one blow?
Capt. Jenkins know that two ships cannot meet going quickly or they will be pulled together. Same for trains, is why one train waits for the other to pass. I grew up by railroad tracks and my mom said that even if I stood close to the train that I could get pulled into the moving train and die so stand way back off the track. An insect hitting your front windshield usually explodes due to the low pressure and dies a nanosecond before even hitting your windshield. Do you know some other examples besides how birds and planes fly?
Pop can activity: Take two pop cans and lay them parallel to each other on a flat surface about a fist apart. Take a straw and hold it parallel to the table so that you do a short quick blast of air from your mouth parallel to the table and watch the pop cans come together like all the stories above.
Penny activity: Lay a penny (any coin really) on the edge of your table and do a short quick blow with your mouth so your wind blows parallel to the pennies surface across the top. The penny will lift and go into a cup or onto your open hand if you do not have a cup. How many coins can you lift with one blow?
Capt. Jenkins know that two ships cannot meet going quickly or they will be pulled together. Same for trains, is why one train waits for the other to pass. I grew up by railroad tracks and my mom said that even if I stood close to the train that I could get pulled into the moving train and die so stand way back off the track. An insect hitting your front windshield usually explodes due to the low pressure and dies a nanosecond before even hitting your windshield. Do you know some other examples besides how birds and planes fly?
Pop can activity: Take two pop cans and lay them parallel to each other on a flat surface about a fist apart. Take a straw and hold it parallel to the table so that you do a short quick blast of air from your mouth parallel to the table and watch the pop cans come together like all the stories above.
Skewer through plastic bag full of water demo.
Water pressure inside the plastic bag seals it. No drip if you do not pull it out or wiggle it.
Skewer through blown up balloon activity
Place tip of skewer in vegetable oil first then spin skewer quickly back and forth (spinning it between two fingers) into the dark part of the top or bottom and through the dark part on the other side. The dark part doesn't rip as easily and the oil helps prevent the balloon from ripping also. If the balloon rips, it will pop. How many skewers can you get through one balloon? Place skewer with balloon in ceiling to see whose last the longest with air. Stand on your chair and then on your table to reach the ceiling or have a tall student next to you help you out.
Smart Notes from today. Siphoning and Bernoulli diagrams were drawn and explained.
The two diagrams this may not work without having the smart board software.