Wednesday, December 22, 2010
Circuits 12-22-10
1. Draw the diagram in your notebook.
.
2. Identify which are in series and which are in parallel. Why.
My answer to question two was that light bulbs A, B, and C are in series because they are all connected by the same circuit. I then said that light bulb D was in parallel because it wasn’t in the same circuit but its circuit used the same batteries as the other circuit. I’m not sure about those explanations on parallel and series so if someone could comment on this than it would be helpful.
3. Describe the electron movement when it is close to fewer light bulbs and when it is close to more light bulbs.
The electron movement gets faster when it goes to the single light bulb (D) and the electrons slow down when they get close to the series of light bulbs (A, B, C).
4. Why does this happen.
I think this happens because there is less resistance when it goes to the single bulb so it can go faster, but when it goes to the multiple light bulbs there is more resistance so the electrons slowed down.
Also don’t forget that we have a quiz tomorrow!
-DB
Monday, December 20, 2010
Fin asked us about self controll. He asked Steve to go up and break a light bulb that he wrapped in a shirt. Steve broke it. Finley passed around the bottom part of the light bulb. Ha asked us if we could trace the path of the wires in the bulb and tell if it was important or not. When we examined it there was a spring on the top connected by 2 rods that went down through the glass that holds everything together. We had to draw what we saw in our notebooks. We also had to answer the ?s "where do the wires go" and "why is it important". We saw that the wires came out of the bulb and did not touch the bottom of the bulb. This was important because if it were to touch the bottom of the bulb, then the electricity would just circle around in one spot. The wires also go out because the electricity needs to find a way out of the bulb to go outside. Fun then passed around the bulb again to see if we could finfd evidence of the wires coming out. My group found where the wires were coming out- one on the side and one coming from the bottom. FIn asked why the wires were going in 2 different places. Then, fin brought back up the whole plastic parachute senario when he rubbed the parachute on Sasha and Yamato's head. He said that when you rubbed it on your hair, you are releasing electrons creating static electricity. He then rubbed the chute onto several people's heads and said that this realeased positive energy. Anthony said that it released electrons that traveled from the desk onto the chute then to the head. We then watched an Irish movie about electricity. In the movie they said that traffic also creates static electricity. Then they moved on to electrical circuits. They said that an electrical circuit is a circuit that makes electricity move around. They gave pictures of circuits. ON circuit, the parallel circuit, has electricity that goes around in a circle. A series circuit is where the circuit goes to more than one place at once. The movie moved on to telephone wires and that good stuff and how the high voltage can kill a person. This happens because the human body is mostly made up of water, and since water has a strong reaction to electricity, the shock can kill a person. Then they explained that a wat is equal to a jewl or newton (Fin pointed that out). THe movie moved to how electricity also creates heat and fuses. They then explained that life would be very difficult without electricity. The movie ended after that. We talked about the movie and their accents after the movie was done.
There is a test tomorrow along with a study session at 7:00- there might be donuts
:-)
WR
Friday, December 17, 2010
Energy and Circuits- P2
Today we went over our homework from Phet.com. Our homework was to create a circuit that lights a light bulb. After creating it on Phet.com, you can see how the current is passed from the battery to the bulb through the wires. In order for the current to work, you need an energy source (battery) and a place for the energy to be recieved (light bulb)with a switch to turn it on. If you have an open circuit, energy cannot be passed through.
A closed circuit is a complete circuit where the energy can be passed through in a circle.
A resistor is a tool that you can add onto your circuit which can slow down your current and dim the light.
If the circuit has a too high of a voltage, it will catch on fire.
Energy cannot pass through a dog.
Energy can pass through metal a lot easier than a non-mental object.
The blue dots that pass through the wires are the electrons. Electrons are a part of an atom. The electrons preform kinetic energy while traveling throught the wires.
Another thing we've briefly talked about was static electricity. After rubbing hair with plastic the result was that it stood up. This is caused by electrons. The electrons from the plastic was rubbed onto hair which made it stand up.
S.D
Thursday, December 16, 2010
8.4 questions; December 16, 2010
8.4 a. A roller coaster pulls the cart to the top of a hill by doing 150,000 J of work on the system. The internal energy of the system changes by 50,000 J. How much more kinetic energy does the system have when the cart makes it back to the bottom of
the hill?
Remember, to get to kg from just grams, you have to divide by a thousand or move the decimal point three times to the left. Afterwards, you have to multiply kg (mass) by 10 to get the force. Once you have found what the force is, you use the formula "Force * Displacement = Work" In this case in 8.4, you have 3g. 3g divided by a thousand is 0.003. Times that by 10 to get force or 0.03. So now, force= 0.03n.
Now, in the formula Force * Displacement = Work, we haven to substitute Force in for 0.003n. Also, work is substituted for 50J. Now we can modify the equation to "Displacement = Work/Force. One J is equal to 1n * 1m.
Force * displacement = Work or Displacement = work/force
0.3n *166.667 = 50j or 166.667 = 50/0.3n
I had to skip 8.4 b so now we are on 8.4 c.
8.4 c. A meteoroid, moving with high speed, enters the Earth’s atmosphere and falls toward the Earth. As it passes through the atmosphere, it warms due to friction with the air. When it hits the ground, it creates a giant crater. Explain the process using any or all of the ideas of work and energy changes (consider all possible types of energy change). Include a work-energy bar chart.
In this problem, the system is the Meteor. We have Kinetic energy in the Initial state with work then added to equal Kinetic energy with Internal change energy in the Final state. In this problem, the earth is doing the work.
8.4 d. A skydiver who jumps out of an airplane at 3500 m above sea level accelerates towards the ground for about 15 seconds before the upward force exerted by the air on the skydiver is about equal to the downward force exerted by the Earth on the skydiver.
a. Draw a force diagram for the skydiver after she/he has been falling for about 15 seconds.
There should be Grav. pot. energy and Kinetic energy. Also, there should be negative work which equals out to less Grav Pot. energy and less Kinetic energy
b. The skydiver’s speed remains constant at 55 m/s until he or she opens the parachute. Choose the skydiver, the Earth, and the air as the system. Draw
a work-energy bar chart that describes the skydiver’s fall from when he or
she leaves the plane until just before the parachute opens.
Comment if I left anything out or messed up anything!
Class work and HW: Go to Google and search for PHET and play Sims
click on first link
go to physics
Then electricity, Magnets and circuits
then go to circuit construction kit
Create a machine that lights a light bulb and explain how it works!
Most likely there's a test Tuesday!!!
BB
Wednesday, December 15, 2010
December 15, 2010
(200N). The differnce between force and work is it takes alot of muscle to exert force and no work can be done.
A.M.
Tuesday, December 14, 2010
December 14 ,2010 - Starting to Going Over Lesson 8
Today in class we started by finishing watching Mythbusters.
After we finished watching the video, we went over lesson 8.
8.1 a) We said that the Americans With Disabilities Act is concerned with the steepness of accessibility ramps because there shouldn't be too much force (not work) needed to go up the ramps. It isn't about work because the amount of work stays the same no matter how steep the ramp is. This is because when the ramp becomes less steep, there is less force but the distance increases.
b) since the ratio for the height and width of the ramp was 1:12, I said that possible ramps are 3m by 36m, 5m by 60m, and 12m by 114m.
c)I said that ramp "iii" fits the requirement.
In class we learned that you can find how much force needs to be applied to something by doing (Mass * 10). This is only true with kilograms so if it is in any other units, it must be converted into kilograms.
d)
i) To find out how much work is done on that ramp, we needed to know that Force * Displacement = Work. Using this rule, Mass * 10 = Force, we found out that we would need to apply 200N. The height of the ramp was 2meters so the displacement is 2m. By doing 200N * 2, we found out that it would take us 400J of work to push a wheelchair up the ramp.
Class ended so we did not go over the rest of problem d)
I was still confused about why we take the height of the ramp for displacement and not how much you traveled/moved the wheelchair
-AT
Friday, December 10, 2010
Decmber 10, 2010 Period 2
http://www.npsd.k12.nj.us/20222069133223760/blank/browse.asp?A=383&BMDRN=2000&BCOB=0&C=59194 here is the link to the page for Energy Activities. Its on the bottom of the page.
GS
Thursday, December 9, 2010
energy activity sheet
Tuesday, December 7, 2010
Tuesdays Blog
Monday, December 6, 2010
Monday, December 6th: Skateboard Problem
a) Draw a picture of your track.
(shown above.)
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Place the skateboarder on the track and observe the motion. You can investigate further by changing the skate or you can scroll down and adjust the fiction. Choose two different situations from the simulation that you can analyze and then share with the class.
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1. My first situation is on Earth, with the PhET skater. The track is my original track shown above, and the friction is none. I observed that the skater keeps on going at a consistent speed and it pauses for the same amount of time when it reaches the ends of the track every single time.
2. My second situation was using a bulldog on the Moon. The track is still my original track, but the friction is medium. I observed that the bulldog wasn't able to move as fast; in fact it couldn't even go through the loop because of the friction. Things on the moon are supposed to be lighter, so friction can really slow someone down.
b) Describe or draw your chosen initial and final states
initial final
c) Include your choice of a systems
My choice of the system is the Earth and the skater.
d) Create three different representations (i.e. picture, bar chart, force/motion diagrams, number statement, graphs, etc) to demonstrate the changes that occurred during the process.
40J + 20J = 20J + 40J
Friday, December 3, 2010
Friday, December 3 - HW Review & Elephant Project
Then, we went back with our groups to work on the elephant project. We started the elephant project two days ago when we watched a video to start us off. The video was about an elephant that steps onto a trampoline. It shows the elephant walking up the steps, and starting to jump on the trampoline and jumping on it. Mr. Finley gave us a task to find 5 things that related to energy from the video, draw the intial and final states, bar charts, and number sentences. There was also an additional question which is: "Is the elephant situation realistic in terms of physics and energy?
You can watch the video at:
http://www.youtube.com/watch?v=TK27aknWVI4.
A.L.
Thursday, December 2, 2010
If you want to see the video go to youtube.com and type in elephant jumping on trampoline
Then we went to a website(colorado.edu) and played a game energy skate park. It was a person on a ramp going back and fourth.
-MM
Wednesday, December 1, 2010
Energy Bar Charts and Project
Here is the video:
Nothing as of 4:30. As we all know, Mr. Finley posts homework by 4:00 so it is safe to day there is no homework.
Here is the webpage
Tuesday, November 30, 2010
November 30, 2010
Wednesday, November 24, 2010
Class on 11/24
I have a question for everyone out there: for the system for the skier problem, why is the mountain not in the system?
Tuesday, November 23, 2010
11-23-10 Elevator problem
- You must comment twice a month
- November and December are going to be combined, so you have enough time to make your tow comments.
- The comments should be either a question or correction.
- Answering a question counts as a comment.
- Your comment should be on a recent blog, otherwise no one will see it and respond.
The picture is what a bar graph would look like.
Next we began to work on a few problems with the bar graph packet.
It was: $20 in your wallet, $60 int he bank, and $20 pocket.
If you take $20 out of the bank, and put it in your pocket what would the bar graph look like now.
We would then draw a picture of the change. This is what the rest of the bar graph packet was like.
Then we got into groups, mine was going over the elevator problem.
Say the elevator is 1000 N and Mary is 100 N the weight now is 1100 N the elevator height is 10 meters, how can you figure out how much work was done?
Force* displacement=work
1100* 20= 22000 J
We got 1100 form the weight of Mary and the elevator, and we got 20 because we drew a picture to help us figure out how much distance the elevator would have to go..
Next we had to figure it out if Marys twin sister was on it, we assume she weighs the same.
Mary is 100 pounds, and her twin is 100 pounds
1200*20= 24000
N=Force
Meters= displacement
If we went on the elevator for 4 floors instead of 3, it would be:
1100*30= 33000
1100 because of the weight of the elevator and Mary, and 30 because of the amount of meters between the floor of the first floor and third.
Something I am a little bit confused on is how to make an integer statement. If anyone wants to comment and tell me how, that would be good.
KK
Monday, November 22, 2010
Thursday, November 18, 2010
Thursday, November 18
The homework problem was:
Eugenia slowly lifts a box by exerting a constant force of 5n. She moves the box from the ground up onto the table, which is 1m high.
Here are the questions on the homework:
1. Draw a picture of intial and final state for the box while she is lifting it.
2. Calculate the work Eugenia has to do in order to lift the box onto the table.
3. Dicuss the energy transformation and write a number sentence to express what occured.
4. Suppose Exerted a larger amount of force on the box at the beginning. What would she have to do to get the box to stop when it got to the table?
We also discussed this question:
Mary rides in an elevator from the first floor to the third floor. Answer the following questions.
Here are the questins:
1. Sketch the intial and final states, and then identify the system.
2. Make a reasonable approximation for the force applied and the distance between the floors in the building.
3. Write an integer statement for the work the elevator does to lift mary to the 3rd floor. Find the work.
4. How much work would the elevator have to do if marys twin sister joined her?
5. How much work would the elevator have to do if mary decided to go to the 4th floor instead? (find the work for both cases: with and without her sister)
-SA
Wednesday, November 17, 2010
November 17th Wednesday Period 2 (Spring Story)
Tuesday, November 16, 2010
Period 2 Energy and Systems
Person dragged along the ground --> work: thing that is dragging the person
INTERNAL ENERGY system: person, ground, earth
The ground needs to be in the system because it causes friction on the ground to heat it up. The earth also has to be in the sytem.
Hot air balloon rising into the air --> work: hot air or fire GRAVITATIONAL
system: earth, balloon POTENTIAL
Car falls off of a cliff --> work: earth system: car KINETIC ENERGY
I am a little confused on how you would find the equation for something like the pogo stick problem so can anyone tell me what they think it would be? Thanks
EE
Friday, November 12, 2010
11/12/10
Thursday, November 11, 2010
• Light Energy
• Mechanical Energy
• Electrical Energy
• Chemical Energy
Next in class we talked about the types of mechanical energy which were:
• Internal Energy
• Gravitational Potential Energy
• Elastic Potential Energy
Gravitational Potential Energy
b) The external force caused the cart to move faster and faster.
Kinetic Energy
c) The external force caused the slingshot to stretch.
Elastic Energy
d) The external force caused the surfaces of the touching objects to warm.
Internal Energy
Then we answered the first 2 questions of the next section.
Monday, November 8, 2010
November 8th, 2010 -Energy Reminders For Test
- No mass
- Many forms of energy
- Can never be destroyed
- It never stops going
Then we came together as a class to see what we all came up with;
Brady's Group:
- Light is energy
- Energy cannot die
- You can apply energy
- You can't apply energy to yourself
And a few more.
Yamato's Group:
- Energy has no mass
- Not a state of matter
- Many types of energy
- Can be transferred object to object
- Can be transferred by applying force.
Steven's Group:
- Work is transferring energy to or from our object or system by applying force and having our object displace
- Force; push/pull
- Displacement; change in position
My group:
See the first list.
Alexia's group:
- Isn't matter
- Transferring energy to an item is work
- Doesn't always displace
- Need energy to have chalk smashing ability
- Types of energy; microwaves, UV rays, gamma rays, x-rays.
JayGee(:
**Remember we have a test tomorrow and there's a study session at 7 tomorrow. Study!**
Wednesday, November 3, 2010
November 3rd, 2010
JG
Tuesday, November 2, 2010
Chalksmashing Ability
-Anthony M.
Monday, November 1, 2010
Light Review/Chalk experiment
Than we decided to go over the discovery of Newton.
The question based on Newton were:
What happens when white light goes through a prism?
People answered that white light would spread in the prism as it bends and since white light is made up of many colors, when it slows down in the prism, many colors appear.
We discussed about how the different colors have different speed and bend more or less
Than we discussed why this doesn't happen with laser
We thought that this happens because the light of the laser is not white but red.
Next we thought about why do we see the object's color? (why is the sweater orange and why is that sweater blue?)
Light hits the object and goes into your eye,
when the white light hits the orange sweater, only the orange light bounces off and other colors get absorbed
We thought about the time we were observing the laser and thought about how when the laser is shined at a black poster, the laser becomes less visible than when we shine it on an orange poster.
We could test the absorption by placing a black colored paper and a white color paper under a glass of water and see what the temperature of the water is.
Than we asked our selves, where do we see the prism effect in real life?
After rain we would see a rainbow we would see the prism and white light effect. This happens because the sun acts as the white light and the moisture in the air would act like a prism and bends the white light
What are the other types of energy?
white light
UV rays
microwaves
x-rays
inferred
Towards the end of class, we placed a piece of chalk under a dictionary and we thought about what would we have to do in order to smash the piece of chalk using the dictionary.
We said that if we drop a book from a distance, the chalk would break. The dictionary would be more able to smash the chalk when it is farther away from the chalk. One student stood on a chair and dropped the book and the chalk did smash
by AT
Friday, October 29, 2010
Cow Eye Dissection
This is my blog for dissecting cow eyes .My partner and I are taking it apart step by step. CS
Thursday, October 28, 2010
10/28 Period 2
Then we went over how a laser reflects and refracts in a triangular prism, and how a flashlight makes a rainbow when it goes through a prism. We went over what a rainbow was and how white light bent to create one. Certian colors of light slow down more than others so that they seperate and turn into the rainbow. When a second prism is held up to the rainbow it becomes white light again. We saw Newton's model of light going through a prism.
http://www.buzzle.com/articles/color-spectrum-chart.html her is an article with a picture of Newtons theory. GS
Wednesday, October 27, 2010
Period 2 Triangular Prism Experiment
- a prediction
- test observations/drawing about what you saw
- conclusion
- observations
- describe what you saw(facts)
- draw a picture that explains what you saw
- Explain why the thing you saw happens
- Relate it to something(analogy)