The Physics Behind Running (1)
As you run, you are moving your legs against gravity, which means that you are creating gravitational potential energy. This creation and release of energy come from your tendon's elasticity. Much like a rubber band, whenever you step, your tendon stretches, therefore storing potential energy. Then, whenever you get off the ball of your foot, your potential energy becomes kinetic energy.
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The Physics Behind Running (2)
Whenever you are running, the highest level of potential energy is at the peak height both, the knee and/or foot reaches. This is because the distance between your foot, and/or knee, and the ground, h, directly affects the potential energy output. It can be proven by the equation:
Potential Energy= (mass)(gravity)(height)
In this case, the values of mass and gravity do not change. However, the distance, or height, between both, your foot and/or knee, and the ground varies as you run. Therefore, as your height increases, potential energy increases.
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The Wheel
Thomas Jefferson and the Metric System
The efforts to introduce a system of measurements based on 10 date back to Thomas Jefferson. It was not exactly the metric system as we know today, but an original system of measures based on 10.
Here is an example of those original units:
Length
"Let the foot be divided into 10 inches; the inch into 10 lines; the line into 10 points. Let 10 feet make a decad; 10 decads one rood; 10 roods a furlong; 10 furlongs a mile"
Weight
"Let the ounce be divided into 10 double scruples, the double scruple into 10 carats; the carat into 10 minims or demi-grains, the minim into 10 mites. Let 10 ounces make a pound; 10 pounds a stone..."
If that does not sound familiar, that's OK. Despite the fact that the idea was supported by people like George Washington and Alexander Hamilton, the system proposed by Jefferson was never accepted.
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Just for the record... Where are we with the units today?
National Metric Day 2017
October 10, the tenth day of the tenth month has been named National Metric Day since 1983.
Get Ready for the Great American Eclipse - August 21, 2017
With the new moon on July 23, the last one before the solar eclipse of August 21, SPACE.COM announced the final countdown.
In New Jersey, the partial eclipse will be visible beginning approximately 1:20 PM through 4:00 PM, with the maximum of about 70% of the Sun covered at 2:45 PM. That will be an exciting 2.5 h of observation and documentation. All are welcome to join us: Obal Hall main entrance, Lodi.
Maria Sklodowska-Curie Monument, Warsaw, Poland
Maria Skłodowska-Curie is
- the first woman to win a Nobel Prize
- the first person and only woman to win twice
- the only person to win a Nobel Prize in two different sciences
The monument is situated in Warsaw, Poland, Skłodowska's birthplace. Maria Skłodowska-Curie is holding a model of an element named Polonium after her homeland.
Someone wrote about the monument, "Pretty statue of an inspiring woman".
An Old Sun Clock
You can tell that nobody uses it... Anyway, I have a kind of sentiment to those old devices.
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Try to make a sun clock on your own. If you have done one, please send me a picture of your homemade sun clock, I'll post it here.
Lesser Known Thomas Edison's Inventions
Thomas Edison is mostly famous for his inventions of the
light bulb and phonograph. However, he created many more things that we still
use today. For example, he made the early version of fruit preservation. He
came about this discovery when he was working with light bulbs and glass vacuum
tubes. To preserve the food, fruit or vegetables (etc.) was put in a glass jar
and then all the air was sucked out by another glass piece so they lasted
longer. He applied for his patent in 1881. This way to keep food fresh led the
way to today’s machines that can be found in any household as vacuum sealers.
Linnea
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One invention that Thomas Edison was a bit less well known
for was the magnetic ore separator. The idea was to use magnets to separate
iron ore from unfeasible lower grade ores. This meant that uninhibited mines
could be lucrative through the removal of iron from sand at the sites. At that
time, iron ore prices had risen to extraordinary heights. While Thomas Edison’s
lab was preoccupied with evolving a magnetic ore separator and putting it to
use; he acquired rights to 145 abandoned mines and set up a pilot project at
the Ogden mine in N.J. He poured money into the development, progressively
selling most of his interest in the General Electric Company to pay for his
work, but the engineering problems were never worked out and the price of iron
ore fell which lead him to abandon the separator.
Maria
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One invention that I was surprised that Thomas Edison
invented was the synthetic rubber that we got to see in the museum’s Chemistry
Lab. Edison worked with many different types of plants to create rubber. He
finally settled on goldenrod to make the best product. I was surprised because
of people, including myself, usually, associate Edison strictly with inventions
such as the light-bulb. It was interesting to learn that Edison also
experimented with plants and their uses. It showed me that he was a very
versatile and innovative inventor.
Kristin
Thomas Edison's successes and failures
Although, Thomas Edison is well known for his numerous inventions such as the light bulb. Within his repertoire of designs, some received less sensationalism. The Electrographic Vote-recorder was an invention patented by Thomas Edison. At age twenty-two, Thomas Edison started his career developing methods for the U.S. Congress. As a means of recording votes in a more timely fashion than the time-honored voice vote system, Thomas Edison developed the electrographic vote recorder. According to Science (howstuffworks.com), the vote-recorder was a voting device connected to the operator’s desk. Embedded in metal the name of the legislators were accompanied by one column representing "yes" and another representing "no." As Legislators moved a switch on the device, this would point to either "yes" or "no," sending an electric current to the instrument at the clerk's desk. At the end of each submitted vote, the administrator would place a piece of paper treated with chemicals on top of the metal type and run a metal roller over it. The current would cause the chemicals in the paper to dissolve on the side for the recorded vote. Wheels kept track of the total votes and registered the results. At the time, Congress was not interested in devices that increased the speed of voting. Consequently, the rejection of Edison's vote-recorder classifies it as one of Thomas Edison failures or less famous inventions.
Elidomi
Thomas Edison Laboratories - Voice Recording
One great invention by Thomas Edison is the phonograph which records your voice and it plays it back. When speaking into the receiver the sound vibration of the voice would cause a needle to create indentations on a drum wrapped with tin foil. The first recorded message was of Thomas Edison speaking "Mary had a little lamb". He showed it to others and from that he produced other amazing things. Like inventing things that help people play music from their homes.
Emelyn
The Black Maria
The Black Maria was Thomas Edison’s movie production studio. Built in 1893, it is known as the world’s first movie production studio. Films were shot using the kinematograph, which was the most state if the art, stop-and-go, filming device of its time. The Black Maria had a huge window on its ceiling in order to let sunlight into the studio because the films in this time period required an immense amount of light in order to be filmed properly. Due to the times, only silent films were filmed, but this studio was still revolutionary in the making of the modern world's entertainment.
Fernando
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Thomas Edison constructed the first movie studio in West Orange, New Jersey. This studio or Kinetographic Theater, as it was formally called, was made out of wood, tar paper, and a roof that opened up to the sun. It was also built on a turntable to allow movement towards sunlight during the course of the day. This studio was coined the Black Maria because its eccentric appearance resembled a police wagon. The Black Maria was a venue in which many short films or motion pictures were recorded. Blacksmith Scene, Fred Ott’s Sneeze, and Sioux Ghost Dance were a few of these films. Later, in 1903, the Black Maria was torn down after Edison built a glass-enclosed rooftop studio in New York City. A replica constructed in 1954, remains in Thomas Edison’s National Historical Park.
Anette
I = I (R)
 |
| The experimental data was collected by Aneta, Anette, Ashlee, Jocelyn, Julia, Lanyse, and Mitchelle
In this lab, students measure current generated by a 1.5V battery in a simple circuit with various resistors. The horizontal axis shows resistance [ohm] and the vertical one shows current [milli-amp]. The colorful dots represent measurements and the green line shows the theoretical line of an equation I = V / R, or, using the math notation, y = 1.5 / x. You can see that the measurements fit the theoretical line perfectly well (small error bars are not visible here).
GOOD JOB! |
Kirchhoff Was Right!
- Any conclusions after today's lab exercise?
- Yes, yeah... Kirchhoff was right!
Two bulbs connected to a battery are dimmer than one on its own
The voltage that dropped on one bulb (Figure 1) is equally distributed between the two bulbs (Figure 2). Also, the resistance of two bulbs in the second circuit is higher than in the first circuit build with only one bulb. Higher resistance reduces the current.
Optical Bench. Finding the Focal Length of a Lens.
Graph by Rebecca
Graph by Shanice and Bernice
Graph by Yonatan
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