Newton's blog

Katie Vaughan
4/25/08
Newton Paragraphs
1. Aristotle believed in the constant of acceleration due to gravity. Aristotle noted that even objects with very different weights would fall at the same rate of gravity. Galileo tested this by rolling balls of different weights down the same sloped decline. This would show the equal acceleration, but at a good speed to observe because it was not free falling. We have studied this with the formula of F=mg. G=9.81 m/s^2 and you can use this to see the force applied or the mass of the object that was free falling. The part of the chapter that pertains to this is stated through, “If you drop two bodies that don’t have much air resistance, such as two different lead weights, they fall at the same rate.” This law does not pertain to air resistance that is caught by such objects such as a feather.
2. Another topic that pertains to our physics class was Newton’s 1st Law, which states that “a body will accelerate, or change its speed, at a rate t hat is proportional to the force.” In Newton’s Principia Mathematica is also known as Newton’s First Law it states this law. This law is related to our studies because of the formula F=ma. This equation is used throughout the physics year to find either the force, mass, or the acceleration. The a is always 9.81 m/s^2, if it is on earth, but otherwise you have to find the acceleration due to that planet’s gravity.
3. The last topic that relates to our studies of physics is of the equation of F=Gm1m2/r^2. This applies because of what is stated in the article, “that theory states that every body attracts every other body with a force that is proportional to the mass of each body.” This topic is given to find the mass of either one of the objects, the distance between them, or the force that is applied. The G is a constant given on the physics reference table. This topic that Newton’s theory of gravity, and we learned about this on physics class throughout the year.

Chapter 20 #63

Above is a cross section diagram of the Leyden Jar. Pieter van Masschenbroek invented the Leyden Jar in 1975. The Leyden Jar would be used to store electric charge. The original jar was made out of a glass bottle, and it contained water to conduct electricity. A metal wire was passed through the cork which was used to close the jar. There was a conducting metal foil wrapped around the outside of the jar and also covering some of the inside surface. The inner and outer surfaces of the jar store opposite charges that are of equal amounts.

Franklin’s bells were used as an original form of detecting when an electrical storm was going to occur. This was because when the bells were connected to a lightning rod, they would ring when an electrical storm was close by. This idea was started when Franklin, during one of his experiments, realized that when 2 differently charged objects made contact with each other then they both would become the same charge. He also found that some things were attracted to charged objects. Using this idea he used a bell in place of one of the objects.

Blog Post #63

Pieter van Masschenbroek designed the Leyden Jar to store electric charge in 1975. It was originally made by okaying water into a glass bottle. The water acted as the conductor. A metal wire was then passed through the cork that closed the jar. The design later changed to used metal foil. The new jar was then chared by an electrostatic generator. The inner and outer surfaces store opposite charges that were of equal quantities.
The Wimshurst Machine, designed around 1880 by James Wimshurt is used to generate high voltages. Two large contra-rotating disks are mounted in vertical plan along with two metallic brushes as cross bars, and also included a spark gap. The electric charge is created through electrostatic induction. These two insulated disks and metal cross bars rotate in opposite directions which create an imbalance of charges. Sparks jump across the gap since the positive feedback increases until the dielectric breakdown voltage of the air is reached.

ch 20 #63

During one of Franklin’s initial experiments he noticed that a pith ball or cork would be repelled if touched together but at would be attracted to a charged object. He realized this because the two objects were initially charged differently, but once they touched they acquired the same charge. He later realized if he replaced the charged object with a bell he could make an "electric bell." Later he used the bell as a lightning detector that became known as Franklin’s Bells. When the bell was connected to a lightning rod it would ring when an electrical storm was nearby, which could be used as an early form of weather detection.

The Leyden Jar is a device that was invented by Pieter van Masschenbroek in 1975 to store electric charge. The Leyden Jar was made of a glass bottle with water to act as a conductor for electricity. It was made with a metal wire that passed through a cork which closed the jar. The design of the jar later added a metal foil coating part of the inner surface and a conductor foil wrapped around the outside surface. The jar is also now charged by an electrostatic generator connected to the inner electrode, with the outer plate being grounded. Additionally, the inner and outer surfaces store opposite charges that are equal in amount.

4/1/08 Blog Post

Heyy, so today we started off by Mr. Wirth reminding to scribes to always be alert! Well this one obviously was, because I remember that we started off with a review sheet he handed us...

We did about 4 problems on the sheet that reminded us of the properties of this unit.
We calculated the amount of charge passing through resistor (R2) in 60 seconds. We did this by using I=delta q/T
Next we learned how to draw a parallel circuit using the ammeter symbol, battery, and 2 resistors of a certain ohm.
Lastly we calculated the equivalence resistance of the circuit by using the equation 1/Req=1/R + 1/R2...

After reviewing these concepts we jumped right into notes...
VOLTMETER: measures potential difference between two points in a circuit.
**these are connected in PARALLEL
**extremely HIGH internal resistance
**draws extremely SMALL current

AMMETER: measures current through ONE point in a circuit...
**connected in SERIES
**extremely LOW internal resistance
**creates extremely SMALL voltage drop


so that was all the notes did for the day... by the way ellen missed all of this because she was not here. so i hope she takes full advantage of this blogging experience...

ok peaceout

Chapter 20 Question 63

Leyden Jar
It is a devide for storing electrical charge and was invented in 1745 Pieter van Musschenbroek. It was the first capacitor and was used to conduct experients dealing with electricity. the design consists of an electrode connected to a metal foil folding part on the inner surface of a glass jar. The conducting foil is wrapped around the outside of the jar which is charged by an electrostatis generator, which is connected to the inner electrode and the outter plate is grounded. Both the inner and outter surfaces of the jar hold opposite charges. Originally it was a glass bottle partially filled with water with a wire passing through the cork that closed it. Benjamin Frankilin found out the charge was stored in the glass and not the water.
Franklin's Bells
During one of his initial experiments he noticed that a pith ball or cork would be repelled if touched together but initially would be attracted to a charged object. he realized this because the two objects were initially charged differently, but once they touched they acquired the same charge. He later realized if he replaced the charged object with a bell he could make an "electric bell." Later he used the bell as a lightning detector. When the bell was connected to a lightning rod it would ring when an electrical storm was nearby.

March 25, 2007

Today we began a new unit called Electrical Circuits, which originated in about 1350-1400. A circuit is a closed loop or path along which charged particles move, in which an electrical current can exist. a cirsuit is formed by a source of potential differnce, including one or more resistances.

Circuit elements include:
Source elements: device or system that can produce a potential difference
Load elements: device or system to which the source is connected
Control elements: used to control the flow of electrical current
Path elements: used to interconnect other elements

Circuit symbols can be found on page 4 of the reference tables

Terms and Definitions:
Current (I)- flow of electric charge, the time-rate at which charge flows past a given point in a circuit.
Unit: ampere (A)
1 ampere= 1 coulomb/second 1A=1c/s
equation: I= the change in q/time