Students don't go to the library any more!
Since the early-90s, computers have slowly increased their connectivity to each other at an exponential rate. The net result is sharing of information.
Students used to rely on large, annual publications called encyclopedias for research papers. The only way to perform well on a research paper was to physically travel to a library (hopefully a good one) and pore through endless racks of books using the Dewey Decimal System. Now, a student can access multiple levels of magnitude more information using the internet. Travel not required. Students are exposed to a multitude of ideas instead of what they stumble upon amidst the stacks. The speed at which these ideas are accessed is much faster. Just 20 years ago, if a student wanted to share ideas with someone else, they either traveled or mailed their thoughts and then went through a cumbersome physical exchange back and forth to achieve the desired result. Today, many minds spread over many continents can instantaneously brainstorm on a project and all of those new ideas are immediately disseminated. No more checking the mailbox to see if the packet from Cologne has arrived.
Saturday, June 22, 2013
#8 Flight Unit
Bernoulli Lift
A phenomenon that occurs when airflow moves faster over the top of a wing compared to the airflow moving over the bottom. A vacuum occurs which move the wing up and generates lift.
Newtonian Lift
An airplane travelling through at speed has air molecules bunching up underneath its wings. The faster the airplane goes, the more this bunching up occurs. The molecules bounce off the bottom side of the wing and push the airplane up.
Airfoil
A special shape of wing that is designed to maximize both Bernouilli and Newtonian lift
Thrust
Early airplanes relied on gasoline powered engines that pushed a piston up and down. This piston was attached to a crankshaft. The crankshaft turned a propeller. The faster this propeller was turned, the faster the airplane would go. As engines became more and more powerful (with more and larger pistons), the airplanes traveled up to 550mph. It wasn't until the jet engine was invented that the sound barrier was broken and engines could create enormous thrust. The ultimate expression of thrust was the Apollo Moon Missions. The Atlas rocket that launched those missions was the biggest generator of thrust man has ever invented.
Propeller
There are a variety of different kinds of propellers. The most simple are blades that are spun around and they bite into the air at a fixed speed. On or off. Then there are variable pitch propellers where the pilot can control how much bite of the air the propeller takes. The pilot can also control how much power the propeller has so it can move faster or slower through the air. When an jet engine is spinning at tremendous speeds and this engine is attached to a propeller, this is called a turbo-prop. Airplanes with turbo-props can fly very fast! They're also extremely noisy as the tips of the propellers are travelling faster than the speed of sound and cause small sonic booms.
When teaching this unit I will have the students create their own planes including paper airplanes and propeller driven models. The purpose of teaching them using hands on experiments allows the students to test different methods and make predictions about flight. Assessment would be done in the form of direct questions and reviewing their science notebooks, looking specifically at their conclusions and reflections.
A phenomenon that occurs when airflow moves faster over the top of a wing compared to the airflow moving over the bottom. A vacuum occurs which move the wing up and generates lift.
Newtonian Lift
An airplane travelling through at speed has air molecules bunching up underneath its wings. The faster the airplane goes, the more this bunching up occurs. The molecules bounce off the bottom side of the wing and push the airplane up.
Airfoil
A special shape of wing that is designed to maximize both Bernouilli and Newtonian lift
Thrust
Early airplanes relied on gasoline powered engines that pushed a piston up and down. This piston was attached to a crankshaft. The crankshaft turned a propeller. The faster this propeller was turned, the faster the airplane would go. As engines became more and more powerful (with more and larger pistons), the airplanes traveled up to 550mph. It wasn't until the jet engine was invented that the sound barrier was broken and engines could create enormous thrust. The ultimate expression of thrust was the Apollo Moon Missions. The Atlas rocket that launched those missions was the biggest generator of thrust man has ever invented.
Propeller
There are a variety of different kinds of propellers. The most simple are blades that are spun around and they bite into the air at a fixed speed. On or off. Then there are variable pitch propellers where the pilot can control how much bite of the air the propeller takes. The pilot can also control how much power the propeller has so it can move faster or slower through the air. When an jet engine is spinning at tremendous speeds and this engine is attached to a propeller, this is called a turbo-prop. Airplanes with turbo-props can fly very fast! They're also extremely noisy as the tips of the propellers are travelling faster than the speed of sound and cause small sonic booms.
When teaching this unit I will have the students create their own planes including paper airplanes and propeller driven models. The purpose of teaching them using hands on experiments allows the students to test different methods and make predictions about flight. Assessment would be done in the form of direct questions and reviewing their science notebooks, looking specifically at their conclusions and reflections.
#7 How a technology has changed over time in response to societal challenges?
The Industrial Revolution in the mid to late 1800s introduced a mechanized means for man to travel over great distances. Before the railroad, man relied on horses and oxen to move materials and themselves over great distances. Once railroads came into widespread use, human civilization exponentially spread over larger areas of the earth. Agricultural areas that were inaccessible suddenly were able to transport their commodities to markets. Resources like wood and coal were suddenly plentiful. The Information Age is a direct result of the Industrial Revolution, and that revolution occurred largely because of locomotive power on railroads.
Image found here: http://cf067b.medialib.glogster.com/media/40/40d7e5b1b11f9e74c1789fac394816e664685f82b009f74f36fd441724e059dd/steam-train.jpg
#6 Cloud Creation
Write the procedure to create a cloud:
Heat from the sun warms the oceans and condenses water into the air. Winds blow this water laden air to other parts of the world. As the water laden air encounters colder temperatures, it condenses into fluffy, white clouds. Eventually, these clouds are blown over land. Rain occurs when these clouds are blown into mountains. The air that is saturated with water bunches up as it's pressed up against the mountains. A measurable point is reached where the air can't keep the water atomized and it begins to accumulate into water droplets. Rain falls, water flows downhill, and eventually that water rejoins the ocean and repeats the process.
This process is repeatable in a lab, and in some interesting cases, an artist's studio. Here's a photograph of a cloud that an artist has made inside of a room using a smoke machine and heavily condensed air. The artist uses a squirt bottle to atomize water into the air. The smoke machine puffs out smoke and the water and particles of smoke adhere together to make clouds. The lighting in this studio makes it even more impressive:
The artist's name is Berndnaut Smilde. His website can be found here: http://www.berndnaut.nl/works.htm
Humans have been making artificial clouds for about 70 years by injecting silver iodide into the upper atmosphere. The presence of this chemical fosters the accumulation of water droplets and increases rainfall. People do this for a variety of reasons: foil warplanes, increase irrigation for crops, provide shade for World Cup tournaments, etc. Other chemicals work, as well, like strontium, but silver iodide is the most common.
Heat from the sun warms the oceans and condenses water into the air. Winds blow this water laden air to other parts of the world. As the water laden air encounters colder temperatures, it condenses into fluffy, white clouds. Eventually, these clouds are blown over land. Rain occurs when these clouds are blown into mountains. The air that is saturated with water bunches up as it's pressed up against the mountains. A measurable point is reached where the air can't keep the water atomized and it begins to accumulate into water droplets. Rain falls, water flows downhill, and eventually that water rejoins the ocean and repeats the process.
This process is repeatable in a lab, and in some interesting cases, an artist's studio. Here's a photograph of a cloud that an artist has made inside of a room using a smoke machine and heavily condensed air. The artist uses a squirt bottle to atomize water into the air. The smoke machine puffs out smoke and the water and particles of smoke adhere together to make clouds. The lighting in this studio makes it even more impressive:
The artist's name is Berndnaut Smilde. His website can be found here: http://www.berndnaut.nl/works.htm
Humans have been making artificial clouds for about 70 years by injecting silver iodide into the upper atmosphere. The presence of this chemical fosters the accumulation of water droplets and increases rainfall. People do this for a variety of reasons: foil warplanes, increase irrigation for crops, provide shade for World Cup tournaments, etc. Other chemicals work, as well, like strontium, but silver iodide is the most common.
#5 Electrical Circuit
The nuclear reactor is the power supply. It's clean, renewable, and only slightly worrisome regarding permanently ruining the environment. The power is transmitted through power lines to the funky boxes in our garages (labeled Fuse Box). The power is divided into circuits. Big ones for the dryer, stove and hot water heater. Small ones for the lights and outlets. The circuit illustrated above is for a simple light. The Switch turns the light on and off by opening and closing the flow of electrons through the copper wires.
#4 Ball Speed
EXPERIMENT:
Find two balls of different sizes and weight (tennis
ball, soccer ball, basketball, etc). Roll each ball down an incline (a slide at
a playground would work). Note length of incline. Time how long it takes for
each ball to get down. Take a third ball of different size and weight and make
a prediction about how long it will take to get down.
PREDICTION:
The heavier ball will get down the ramp faster.
OBSERVATION AND DATA:
I used a tennis ball, a size 5 soccer ball, and a plastic playing ball in this experiment. At first I timed the balls rolling down the 8ft incline with a stop watch. My results were all over the place. Please see table below:
I accounted this to human error. I then decided to race the balls. I did two balls at a time. The tennis ball beat both balls down the ramp each time. The pink ball beat the the soccer ball down the ramp.
CONCLUSION:
Given the shortness of the inclined track (8 ft) and the fact that I timed these using my eyes and a wristwatch stopwatch, human error has really creeped into these results. It's hard to discern what the fastest ball was, however, the tennis ball "seemed" to be the fastest followed by the pink smooth ball. The soccer ball was last.
Human error and lousy time keeping aside, there are three main factors going into what ball reaches the bottom of the incline first.
- Friction between the surface of the ball and the surface of the plywood.
- Air resistance against the different balls.
- Mass of each ball.
The balls are going to roll down the incline at the same rate regardless of their mass because with only 8 ft. to go, they never reach terminal velocity. The air resistance is negligible with such a short run. The friction was different between the three varying ball types. So, even though the times are all over the place, one can generally see that the tennis ball was the fastest followed by the pink ball. The soccer ball brought up the rear.
#3 Classroom Recycling Poster
RATIONAL:
This poster is a way to remind students to always be aware of what they are throwing away. I would place it near each trash can in the room at eye level so that the students would always have to question what they are throwing away.
#2 The Water Freeze
EXPERIMENT:
Place a bowl of almost boiling water and a bowl of cold water in the freezer. Which will freeze faster?
PREDICTION:
The cold water will freeze faster because it has a lower starting temperature.
OBSERVATION:
- After 30 mins there was no ice in either container.
- After 1 hour the cold water was starting to show signs of freezing.
- After 2 hours the cold water had more ice than the almost boiling water.
CONCLUSION:
Cold water freezes faster than hot water.
RESEARCH:
While reading about this topic I found that there are cases where hot water may actually freeze faster than cold water, but the conditions have to be just right. If I had put the exact same amount of water in two identical pans then the hot water may have frozen faster. This could be due to evaporation of the hot water. As it cools it looses mass due to evaporation, allowing it to freeze faster because of the reduction in mass.
#1 Cloud Observation
Experiment:
Go
outside and observe the clouds in the sky for two days. What do you see?
OBSERVATION:
During the past two days, when I have looked at the clouds in the sky, I have seen cirrus clouds fairly high in the sky. I looked at the weather forecast and it said it's supposed to rain heavily for the next six days.
RESEARCH:
This means that these cirrus clouds I'm looking at (along with the nice 70 degree weather we've had) is part of the high pressure front that's in front of this incoming storm. When the rain arrives, it's because of the low pressure system that, like a vacuum, sucks all the clouds and wet weather with it.
PREDICTION:
Starting tomorrow, the clear skies will go away and we'll have a heavy overcast until the next high pressure system pushed the low one out of the way.
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