January 31, 2011 - Reviewing Matter HW (review for quiz)

When we first got to class, Mr. Finley announced that the quiz that he told us about on Friday will be postponed to Tuesday, February 1. Then, he checked the homework from Friday, and we went over it as a class. The homework was about reviewing matter.

It was about the speed of particles moving, and how particles relate to the different types of energy. For the first question, it was about someone trying to open a jar, and they ran it under hot water. To demonstarte what the particles would do in cold and hot water, Mr. Finley did a demonrtation. 4 people stood in a line, shoulder to shoulder, tightly (they represented particles) and they started to "vibrate". This showed how the speeds of particles change from fast to slow or slow to fast. It also demonstrated how the particles tend to expand from each other.

For another part of the question, we had to draw particle pictures. Below are the ones from class:

The next question related to thermal energy. You had to rub 2 pieces of paper together, and explain why the temperatues incresed. It rose because the particles on each sheet of paper bump into eachother. The internal energy/thermal energy was increasing, as someone said. Next, we had to make a bar chart. 1 sheet of paper was the system, so it was doing work. The bar chart that the class made together was:

**the heating symbol in a bar chart is: Q

The bar chart basically explains:

Intitial: The paper didn't have energy because there was no work/heating being done

Work/Q: The papers were rubbed together, so it created heat

Final: The end showed the same amount of energy that was there while the papers were rubbed together.

Next, we discussed why the temeperature cooled down after it was rubbed. Someone in the class said the energy was transferred to the air (the paper was heating the enviorment). Mr. Finley decided to relate it to real life. So he asked what what we mean when we say "heat". Somebody answered that we mean "hot air". So, this proved that by rubbing two things together, its not making you feel heat, it is really making hot air around the objects, so you feel that. After doing that, we learned how to draw a bar chart with negative thermal/internal energy. It would look like this:

Initial: Some thermal energy

Work/Q: Lose part of the existing thermal energy

Final: Only a little thermal energy left

Finley went back to energy transfers and compared school to it. He said that after school when he is working, and no one is here, it's colder. The energy isn't transferring because there are not any people moving around and causing a lot of energy.

The last part of the homework was the lemonade problem. It was a situation about cold lemonade in hot water. Finley wanted to know why the temperatures became the same. The difference of the hot water transferring energy and the energy steeling energy lead to the temperature change in the lemonade situation. It went from warm to cold which brought us to the 2nd Law of Thermodynamics. The 2nd law is getting an equal lybrium. In this 2nd law, energy always moves from warm to cold (high to low). The first law was the transferring of energy concept.

That was all that we did in class today, but we have homework. It will be posted on Mr. Finley's website. He told us that it is about finding 3 types of heat. Before we left he gave us 2 hints though:

***2 of them start with the letter C, and the other one starts with R.***

-A.L. (3rd)

In Class today we went to the Phet website. Then go to play with sims, Then go to states of matter. First he wanted to see what would happen if we put an icecube on a counter. We councluded that if you do the particles would start to heat up and vibrate faster. The next question was what would happen to the motion of the particles if it changed from solid to liquid. Also if it changed from liquid to gas. We said that the particles were vibrateing and spreading out.


-MM

MA 1-25

Today in class, on 1/25/11, we did many things.

First, we did a practice problem for density: a soup can, with radius=2cm, h=5cm, and the mass=300g. We had to find the density. In order to, Finley gave us a cool pneumonic device to help us rememebr formulas for circles and cylinders: for a circle, it's 3.14r(squared), and since a cylinder is really a bunch of circles on top of each other, you multiply that equation by the height, h. You get 3.14r(squared)h. The density was 4.78 grams per cm.3

We also went over the homework. It would be hard to put up all the answers here, but i'll put some of the conclusion questions:



2. An object with a density of 0.67 kg/L would float 2/3 underwater.

3. A floating object has an upward force that is equal to the downward weight.

4. What would happen to an ice cube if it was dropped into a glass of 100% ethanol (density= 0.789 kg/L)? Would it be pushed up more or less? Why do you think this?

It would be pushed up more and down less. It would be because, if you look at the data, you can find this rule: if the object is less dense than the liquid, it floats. Contrariwise, if it is denser than the liquid, it will sink more.

http://en.wikipedia.org/wiki/Density
that helped me understand some of it.
-MA
3rd

1-24-11 Density

Today in class we got back our test, and packets.
Notes:
The amount of particles is the mass.
Unit Rates:
In order to compare, the unit rate must be the same.
mass: 1 unit of volume

mass
---- = density
volume

You have to make the unit to 1, because it is easier to compare to the volume that way. The goal is to compare two masses.

Next we went online to phet. We are supposed to answer the questions posted on the website for homework.

To get to phet, you google phet. Then you click on play with sims, then density, then run now.

The website is below:
http://phet.colorado.edu/en/simulation/density"
In class, we began this while working with a partner.

We came up with the formula that density = 100* the %

KK this is my 3rd blog

January 21,2011-- Denisty

What is density?

-- Amount of particles or mass

-- To find the volume, you multiply length*width*height.
-- The size of the object doesn't change the density. Like materials will have the same amount of density even if one object is bigger than another for example, a life-size gold Jenna statue versus a a solid gold ring has the same density

Unit Rate example: x miles per hour (for every hour, your drive x miles)

To be able to compare, you have to "minimize" the volume down to one.

------------------------------------------------------------------------------------------

This is a bit of the packet we worked on showing how to reduce a ratio.
21.6 g : 8 cm3

2.17 g : 1 cm3-------> 2.7 grams per centimeter cubed

------------------------------------------------------------------------------------------

milliliters cubed is another way to measure volume

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Reflection: Because of the activity with the floating/sinking cubes, I now much better understand the concepts (mass, density, volume, etc..). The packet also helped me becasue I had to figure a out the mass using only the volume and density, for example.


This is an example of the website we worked on where all the cubes had the same amount of density.

JF 3rd

Wednesday's packet review (1-19-11)

Today (Wednesday) we had to finish our packet by the end of the period because it will be graded as a quiz. Last week we worked on all of 5.2 and 5.4 with the sub. Yesterday since it was a delayed opening and we just got back from the weekend, we weren't expected to finish the packet thus making it due today.

Overview of the packet:

5.1

examine a book on your group's table.

a. We thought the book (our book) resembled a rectangular prism

b. You can learn about it's length ( 25.5cm), width (20.5cm), surface area (522.75cm^2, 102cm^2, and 82cm^2), volume (2091cm^3), and depth/height (4cm).

c. Perimeter to SA is basically the distance around an object/shape to the unit per area inside the object/shape. Area to volume is basically the same thing but 2 dimensional to 3 dimensional.

d. the volume of the book is 2091cm^3 and we got it by the formula l * w * h = v.

e. yes, there is a formula to find the volume of a soda can (cylinder) by h * c * r^2 = v.

f. No, you can't use the same approach to find the volume of a water bottle because it is made up of multiple 3d shapes instead of one.

5.2

a. Volume to length is practically 3d to 1d because length only measures one line. V to A is, like I said earlier, 3d to 2d. we measure volume in cubic centimeters.

b. There is more than one way to measure the volume of the given object (ping pong ball, coin, a toy, and a dice). A few ways are to use an overflow bucket, use a formula with any variables needed, or a graduated cylinder.

c. Answers may vary

d. You can write down the result of each measurement by adding the uncertainty. Also, if it is compared together with two different units, then you can transform the units into one and then add the uncertainty.

e. answers may very

f. answers may very but your answers should either be the same or close enough to compare.

g. answers may very but uncertainty added to each result should make both the same or even closer.

5.3


It is important to have many ways to find the volume of an object to double check your results and to give you a better understanding of the experiment.

5.4 (if I get an answer wrong you can explain the correct answer below)

a. 0.016666 repeating hours are in a min. 60min = 1hr

b. 1L = 0.2642 gallons 3.785L + one gallon

c. 1,000g = 1kg 0.001 kg = 1 g

d. 1,000,000cm^3 = m^3 0.000001 m^3 = 1 cm^3

e. 1cm^3 = 1ml 1ml/^3 = 1cm

Sorry that I couldn't post this yesterday. Comment if you have anything to say or anything to add!

BB (3rd Blog)

Density- P2

Today in classs we reviewed and learned more about mass and particles. To start the class off, we were to look at this table:

Mostly evaporated-(volume) 1000cm^2 (mass) 100g

Open to air-(volume) 1000cm^2 (mass) 1000g

Pumped with air-(volume) 1000cm^2 (mass) 1100g

Throughout the graph, the volume stayed the same, but the mass increased.

To see a visual example, Mr. Finley placed a slightly inflated rubeer glove inside of a jar. He then asked "What will happen if we pump air out? After testing this experiment, we found out that the glove inflated with air and increased in mass.

Things to Remember: Dense- amount of particles in one place.

Mass- particles

SD

Burning Paper On January 11, 2011

First, we reviewed what we did in school Friday. On Friday, we dissolved sugar into water to see if mass is conserved. We found that mass is conserved. We made the following lists.

Things that are conserved:

-energy

Things that aren't conserved:

-volume--->empty space issue

-mass

Terms to know:

volume- the amount of space something takes up.

mass- the amount of stuff (matter) something is made of.

To find someone's weight without a scale, you could lift them up. This doesn't work in space because he doesn't have any amount to push or pull something. This is your weight.

Difference between mass and weight:

Mass won't necessarily go away, but weight could.

Mr. Finley takes a piece of paper and crumples it up. Has the mass changed?

No, the volume changed. The mass didn't change because he didn't take anything away.

When he lights the paper on fire, the mass does change because the fire is consuming the paper. There ended up being less of the paper left. The mass is going to decrease because the paper is turning into gas. The evidence is the smoke rising from the fire that is burning the paper.

In conclusion, today we learned about the mass and volume of different objects. Mass isn't specifically the weight of someone or something, but the amount of matter it is made out of. The volume is the amount of space something takes up. These two terms represent completely different things and make up the characteristics of an object or person. When you take away some of the mass from an object, the weight decreases. We figured this out being using the scale we have in class to measure paper before and after it is burned. Now, since the paper is smaller in size, it has less volume as well, and takes up less space.

http://answers.yahoo.com/question/index?qid=20091215213423AAbDi9p

Here is a link to a very important question that deals with what we learned about today.

EC

Third Round!!!!!!!

Hi everyone! Today is January 7th.


First we continued to go over yesterday's homework.


EC said that when you pump a basketball up, its not really
full because the particles inside are all moving around

GS continued her thought saying that air has a lot of empty space in it.

To test whether it is full or not, we could try to pump more air into the second picture.

Then we drew these two pictures. The first is before we pump more air in, and the second is after we pump more air in.

The dots represent particles. There are more particles in the second than the first. This diagram does not include arrows to show direction and speed, but the particles in the first go much fatser

DB asked a good question. "Why, if the particles are moving, doesn't the ball change shape?"

That brought us to the balloon question from last night. As we pump air into the balloon more particles go in, move around, and push the sides of the balloon out.

SA and Finley each pushed on a piece of paper. SA represented the air pressing against the outside of the balloon and Finley represented the air pressing on the inside. The paper didn't move so the balloon doesn't expand. Then Finley stopped pushing so SA moved the paper forward. This shows that the balloon would expand.

When you are blowing it up the push on the inside is stronger than the push on the outside. That is why it expands. When you stop blowing the force on the inside and outside are equal. That is called an equilibrium. When you put it in a vacuum, the force outside is less than than the force inside again.

Then we went over the cup question. Finley held up a cup and asked if it was full.

MA said it was full of air.

To test this we would turn it upside down and slowly push the cup into water. We put a paper boat on the water and pushed it down.

We did this test in class. The boat did not get wet once we brought the cup back up. A tiny bit of water was in the cup

In short the water did not go into the glass because the air was pushing again the water and the water was pushing against the air.

The reason a little bit of water did was because air is partially empty space. The water was trying to compress the air so it could get in. That is why there is less empty space at the end and a little bit of water got in.

This is like an old scuba diver helmet that contains air and water can't get it.

It is also the same concept with bubbles. The particles of air are very compressed so the bubble has a lot of force pushing outward.

Then we started talking about conservation. Its like energy. 10J K + 10 J Ug always equals 20 J.

Volume is not conserved because when you add 10 ml of some particle that can get absorbed by water to 10 ml of water. You will NOT get 20 ml of stuff.

When something can's go into the water it still will not be conserved. The water goes into the other material.

Its like sand. The water goes into the sand. Like at the beach, the sand by the water is wet.

Then we tested whether mass can be conserved.

Finley poured 306.2 grams of water into a graduated cylinder. The cylinder itself weighed 52.2. We have five grams of sugar. What would happen? Will we get 311.2 grams? We checked. It was 311.1. Because of uncertainty mass is conserved.

This weekends home work is... NO HOMEWORK!

I have a question. If you put a solid in water with no empty space, would the volume be conserved? Finley said volume is never conserved, but in this case, where would the water go?

MK (post 3)

1/6

Today we mostly talked about the homework. The homework was if you have 100 mL of water and add ten mL of sugar/salt to the water, using our idea of partcles, what should happen? My groups prediction was that the sugar particles would go into the empty spaces and dissiper. The final mesurment would be 110 mL. Our prediction was half wrong half right. What the sugar did was it only went up five mL and the mesurment was 105 mL. What happened was it went into the empty space in the water. The reasont it went up at all is because it ran out of space. Anthony M.

January 5th 2011

We were talking about the alcohol/paper in a vacuum problem today. The question was "Why did the alcohol disappear quicker with no air than with air?"

My group came up with this hypothesis.

• Particles move faster with air. No air particle get in the way

Then the whole class joined together for a group discussion.

Davis said: Without the air there is more room and less resistance so it leaves the paper quicker. And it turns out it was a lot of group's hypothesises. Just different wordings.

Finley then said that that alcohol is made up of parts, like particles. Any thing that makes stuff up. Particles want to move, they don't want to move. They're naturally in motion.

Finley brought up a group and a single person. The group was blocking the single person from doing what he needed to do. It made it harder for the single person to move through the group.

We proved that the alcohol dried faster in the vacuum.

Finley brought another group up and put a chair and a container of ammonia with a group of people around it. It was a group of about 8-10 people. 4-5 girls 4-5 guys. They were instructed to raise their hand when they noticed something. 3-4 guys raised their hands.

Afterwords, we wrote down this;

• Hands rose very randomly
• In general, spread from middle outwards. (Not a perfect pattern)
• Shorter people got it first.
• JF & KK never detected the smell.
• Papi detected it 3rd.

The particles were explored farther;

• they move freely
• they move in a random manner
• they move in a direction.
• moves at random speeds.

Then we revisited the homework question:

If your mom is making pizza on the first floor and your on the second floor, how do you know what she's making for dinner?

A classmate said that you know what she is cooking because the particles in the food makes the scent.

Class ended soon after that. The homework is posted on Finley website.

JG

Monday January 3,2010- Observations and Mechanisms

Today in class, we talked about mechanisms and how to make proper observations. First, Mr. Finley added a liquid to a piece of notebook paper and told us to take observations. He said that observations should be things that we can sense with our five senses. Observations shouldn't be things we think that we know or assume, observations should be fact only. Then we began to take observations on the liquid on the paper. These are some of my group's observations:

-where the liquid hit the paper, the paper turned a darker shade
-the liquid smells like rubbing alcohol
-the paper gets wrinkled where the liquid touches the paper
-the liquid is disappearing
-the larger the spot of liquid, the more time it takes to disappear
-when the liquid was on the colored lines of the notebook paper, the lines blurred

After that, Mr. Finley told us that so far this year, we have been making explanations about the things that we have experimented. Explanations -------> why things happen. He said explained that we were now going to make mechanisms. Mechanisms -------> how things happen. Mr. Finley explained that mechanisms can be crazy ideas, but they have to be testable.
He started us of with an example mechanism for the liquid on paper. Ex. The table soaked up the liquid(the liquid went inside the table). We then started making mechanisms of the liquid on paper at our groups.These are the class's mechanisms

1. It went inside the paper
2. The air took it
3. Some other organism took it
4. When people smelled it the liquid on the paper for observations, it went up their noses

Lastly, we began to test our mechanisms. We made a chart with three columns. Th first column was the mechanism column, second was the test column, and the last column was the prediction column, when you think you are right. We only had time to fill out the chart for the example mechanism.

mechanism column: the table soaked the liquid up

test column: take the table away and repeat

prediction: the paper should stay wet

Before we could actually test the mechanism, the bell rung.

Some advice if people are getting mixed up with explanations and mechanisms. Think of them like this:

explanations=why
mechanism=how

There are some pictures of liquid on paper on the top of the of my post taken at 20 minute intervals.

CS