QUESTIONS ON DERRY
1. How are change and continuity a part of science?
Change and continuity are major [[#|parts]] of the field of science. Science is always changing, with new discoveries and developments. Continuity is also important because scientists a lot of the time build off the ideas of others who came before them and continue their work, such as when Copernicus used math procedures similar to those of Ptolemy.
2. Although Ptolemy's system is no longer the accepted view of the universe, was his system "unscientific" by modern standards of science? Explain.
I think it is very difficult to declare something "unscientific." This is because the field of science is so broad. Also, although Ptolemy's system was no necessarily correct, it still led to progress. If Ptolemy had not developed his theory so thoroughly with mathematical evidence and a specific procedure, it would have been much more difficult for Copernicus to develop his theory of a heliocentric system because he used Ptolemy's math as almost a guideline.
3. Was Copernicus's system an improvement over Ptolemy's? Why?
Yes, Copernicus's system was an improvement over Ptolemy's. This is not because Copernicus was correct, because the packet states that is math was wrong and his theory was based on old and incorrect ideas. It is more because Copernicus's theory was more groundbreaking, and changed the face of astronomy. It started a very revolutionary astronomical debate over what system was the one we were living in. Copernicus laid down the groundwork for scientists such as Galileo and Kepler to expand off these ideas and make new discoveries.
4. In what ways have scientists' preconceptions gotten in the way of science?
Scientist's misconception can get in the way of science because they can alter a procedure because they are expecting certain results. Also, they may perform an experiment many times because they weren't expecting the results they got. This was evident in Copernicus's discoveries. Although they were radically different from any previous discoveries, when he got different results and developed a theory for a new system, his explanation was an issue because his preconceptions. Although his results were new, he based his explanation off old and incorrect misconceptions.
5. A common conception is that scientists work alone and in isolation from other ideas. Do you [[#|agree]]? Why?
I don't agree. I think that most if not all experiments come from a previous discovery. This was evident when Copernicus built of Ptolemy, and then Kepler and Tycho Brahe built off Copernicus, and it seemed to be a cycle. A scientific discovery can usually lead to further discovery. All ideas have to start from somewhere, and very often that somewhere is the work of a previous scientist.
6. How does technology affect progress in science?
Technology affects progress because it allows for improvement in experiments. With technology, experiments can be performed faster and more efficiently. There can be more precise and accurate conclusions drawn from an experiment using technology. Experiments with technology are much more precise than experiments using simply human judgement.



PROJECTILE MOTION ASSIGNMENT

1. Horizontal distance- each frame is 1/15 of a second
Time:
Horizontal Distance:
5.1333s
10 cm
5.2s
30 cm
5.2667s
37 cm
5.333 s
53 cm
5.4 s
70 cm
5.4667s
90 cm

chart_1.png
As you can see in the graph, the points move in a relatively linear fashion.It is easy to tell the linear motion, therefore showing that the horizontal velocity is constant, and when calculated using the table, it is around 300 cm/s. I do not have Microsoft word so I could not add in a [[#|trend line]], but the linear motion is fairly visible.

2. Vertical Velocity, each frame is 1/15 of a second
Time:
Vertical Distance:
5.1333s
84 cm
5.2s
79 cm
5.2667s
75 cm
5.333s
60 cm
5.4s
40 cm
5.4667s
18 cm


The graph and table show that the velocity is not constant, but rather increasing and accelerating at a rate that should be around 9.8 m/s^s
The wiki would not let me upload my graph, but it is on my email and I will try to produce in class.
ice, ice, baby.jpg
Ali's Dream Job



UNIT 6: WORK AND ENERGY
Work can be defined as the force applied on an object while it moves a certain displacement. If work and displacement are in the same direction, work is positive. If they are in opposite directions, work is negative. Direction is relevant when calculating work because it is a dot product, which means that the parallel component is the component factored into the equation for work.
Work can only be done when there is displacement of the object that the force is acting on. Work can also be defined as the change in kinetic energy. Kinetic Energy is determined using mass and velocity. Potential Energy is the potential work that could be done, and it is defined using the height of the object, the mass, and the acceleration due to gravity. The total energy of an object is the Kinetic Energy plus the Potential Energy. The Law of Conservation of Energy states that energy cannot be created nor destroyed. Therefore, the total energy an object begins with is equal to the total energy an object ends with. The following images help explain the above concepts:

work.jpg
external image weppri.gif

u5l2b21.gif external image Untitled.png

An example of an investigation that could be done to further understand the concept of work and energy involves a roller coaster. This lab would involve a smaller scale model roller coaster, a marble, and ruler, and a timer. Students would measure the diameter and mass of the marble and use photogates to determine how long it takes for the marble to travel the length of its diameter as it travels down the roller coaster. Using this data, students can measure the velocity of the marble and determine its Kinetic Energy. Students can also measure the Potential energy at that same point. Using this data at various points on the roller coaster, students can add the potential energy witht eh kinetic energy and see if all of their total energy are relatively the same. This increases a student's understanding of the Law of Conservation of Energy.

EXAMPLE MULTIPLE CHOICE QUESTIONS:
1. A 25-kg box starts moving at 5 m/s and due to friction ends at rest. How much work is done by friction?
a) 125 J
b) 5 J
c) -125 J
d) -5 J
e) 0 J

2. A 7 kg object is pushed with a force of 10 N for 8 meters. What is the work done on the object?
a) 56 J
b) 0 J
c) 70 J
d) 10 J
e) 80 J

3) A 10 kg object moving 5 m/s to the left experiences a force of 7 N upward. How much work is done by this force?
a) 0 J
b) 50 J
c) 35 J
d) -35 J
e) 70 J

4. An object moving at 6 m/s has a kinetic energy of 18 J. What is the mass of the object?
a) 3 kg
b) 1/3 kg
c) 2 kg
d) 1/2 kg

5. A 20 kg block is pushed for 10 m with a force of 5 N at an angle 45 degrees above the horizontal. What is the work done on the block?
a) 200 J
b) 35.35 J
c) 70.71 J
d) 100 J
e) 50 J

Open Response:
external image images?q=tbn:ANd9GcRfLlN8Fojf8Fc4DDbYQXIgu-fOhT2W6Lz2K9vBG89uFypPC5bPKg
Mass of cart: 10 kg
Height at Point A: 75 m
Height at Point B: 0 m

a) What is the total energy of the cart if the it is at rest at point A?
b) What is the total energy of the cart if it is moving at 39 m/s at point B?
c) At a point in between points A and B, and cart is at a height of 60 m. What is its potential energy?
d) At that same point, the cart is moving at 17 m/s. What is the kinetic energy of the cart?
e) At that same point, what is the total energy? How do all of the total energies compare? Explain.

John Bailey Part II April Vacation Assignment

Answers

1. -312.5J? w=1/2mv2
2. E
3. A
4. 1kg? w=1/2mv2
5. B

A. mgh=U
(10)(9.8)(75)=U
7350J=U
B. w=1/2mv2
w=1/2(10)(39)2
w=7605J?
C. mgh=U
(10)(9.8)(60)=U
5880J=U
D. w=1/2mv2
w=1/2(10)(17)2
w=1445J
E. U+KE=Et
5880J+1445J=Et
7325J=Et
All of the energies are approximately equal. This is because energy is conserved.

Suggestions

1. It may be more helpful to more clearly state the equation for U and explain it to the reader.
2. The multiple choice questions were similar, but with different numbers. In the future it could be beneficial to have different types of problems.
3. The open response questions seemed short. It may be helpful to elaborate on the questions and make them more complex.
4. The pictures and diagrams were very helpful in explaining the concepts.
5. I liked that all of the questions required calculations because I think that that is my weakest aspect for the AP test.