Potential and Kinetic Energy Roller Coasters

We finished our unit on matter and have two weeks before Christmas Break left, so why not start a new unit, right??  I'm just focusing on a small point (potential and kinetic energy) and hoping that they'll retain that information when we come back after the break!

I only saw the eighth graders twice this week (as we're on an every-other day schedule), so the first day we introduced the ideas, took notes, and then spent a lot of time on this website exploring the relationship between potential and kinetic energy:

http://phet.colorado.edu/en/simulation/energy-skate-park-basics

 

It's a great resource that the kids love as well.  There are different ramps, and option to add or take away friction, and a space to make your own ramp.  The last option, where we were creating our own ramp, was the best part because we could have a lot of teaching opportunities with that––why something worked or didn't work, why the boy couldn't make it through the loop, why he fell off at the end, etc.  At the end of one of my classes there was a little bit of extra time so a couple of kids came up and made ramp options that were ridiculous but fun all the same. 

 

 Day 2 was applying what we learned last class to their own roller coasters.  The rubric was as follows:

20%: Draw a roller coaster that is neat, colorful, and could actually be built in real life.

40%: Have a Potential/Kinetic/Total Energy graph at four different spots on the roller coaster that accurately represents the energy at that spot. Write a quick sentence explaining what the graph means there.

40%: Write a short paragraph explaining what potential energy is, what kinetic energy is, and how they relate to each other on a roller coaster.

The kids did pretty well with this.  I have a few stragglers who aren't done (and one student who is autistic and he's been so focused on getting his roller coaster drawn as awesomely as he can that he hasn't accomplished anything else. *sigh*), but for the most part, I think the kids enjoyed this creative project and I think that for special education they showed good understanding of the concepts.  So I give this lesson two thumbs up. 

Here are some examples of finished (or near finished) products:

 

On the wall outside.  I told the students at the beginning that this would go outside, so they should do there best.  They also wrote their paragraph on a separate sheet of paper first, and I helped correct it for spelling and accuracy so that good work was put outside for them to display.   When more kids finish I'll put them to the left of these posters.

Separating Mixtures

In follow up to our lessons on elements, compounds, and mixtures, we talk about how we can separate mixtures.  Our curriculum requires us to teach 4 different separation techniques: filtration, evaporation, magnetism, and screening.

The first day I introduce this, I give small demonstrations of each one. 

• I make a mixture of salt water and have that boiling throughout the lesson until it's all gone and only the salt is left.  
• I have a screen and put a mixture of rocks and dirt through it.  
• I have a filter and put some stuff through it. 
• And then this year another teacher let me borrow her mixture of iron filings and sand with her magnet, so we got to show the kids that one as well.  (I also took the kids outside and showed them that the magnet will pick up the iron in the dirt.  One kid came back the next day and said he tried that in his backyard and it worked. Happiness.)

We don't spend much time on this, so there's just a few activities plus a couple of worksheets.  Here's the worksheet I created for this:

Click below for worksheet

Blast Off!

A few of the rockets my students made.

The eighth graders are done with middle school and are moving on.  During the last few days we completed our Forces and Motion unit by building rockets and shooting them off.  Mr. S has done this for years.  He build his own rocket launcher using PVC pipe and an air pump.  The rockets shoot off from all of the air pressure built up.  He has extra PVC pipes to use when building the rocket so the kids can make sure they have the correct diameter needed.

The day we made these was also my birthday.  I received some nice wishes and a note on my whiteboard:

They're simple rockets made from card-stock paper, but it was lots of fun.  A few of the kids made rockets that flew up really high and over the school fence. Most went a little ways up.  Others totally failed and only the top cone blew off and the rest of the rocket remained.  It was a fun last activity, though.

Mr. S ready to blast off another rocket.

8th Grade Final Exam

It's been a while.  But I feel the end of the year is like that.  I'm not really going over anything new, we're just reviewing everything we've already done.  And then there are a lot of activities and meetings towards the end of the year.

Does anyone else feel like the end of the year is both a drag (still 3 more weeks left??) and a sprint to the finish (only 3 more weeks left??)?

Today my eighth graders took their final exam.  My first class left me very pleased with the results.  More than half the class received A's and B's.  That's awesome.  I don't give easy tests and I expect a lot.  So I was very pleased.

My second class was not as good. Only one kid passed, and he passed with a 95%.  How can there be that much difference?  This class is hard to control, they're often yelling at each other, and don't always try their best.  Even during the exam they were asking why they couldn't take notes (um, you don't even have any??) because "all" of the other classes let them use notes.  Well, looking from experience, I've never let you use notes on a test, so why would I let you use notes now?  I want to see how much you have learned, not how well you can take and read your notes.  Needless to say this second period was difficult and hard.  I don't think I'm entirely to blame, but I do have a lot of notes on how I'm going to improve next year.

After all, I'm a brand new teacher.  There is much room for improvement.

Here's my copy of the eighth grade exam.  I was quite pleased with it.  :)

How well would you do on an eighth grade science test?

Explain the Forces

The first day I introduced forces, I also did this worksheet with the kids. We all discussed it together to come up with the answer.  I would write the answer down on my paper that the kids could see on the projector, and they would also write the answer down on their papers.  The last part I had them do themselves.  It's a pretty self-explanatory worksheet, so you can let your kiddos do it on their own if you want.  My reasoning for doing it with them was to have a little more guided practice to let them become confident in the idea before they did their own worksheet.

Again, disclaimer: This is not mine!  I found this on one of those wonderful teaching websites with free worksheets, but I wasn't good enough to trace my sources so I can't link you to the original website.

Get the worksheet at the bottom of the page.

I had a few kids telling me that was their car, and asking how I got a picture of it. :P

What is a Force?

I have loved this unit with the 8th graders.  There's something concrete about this idea that the kids can really hold on to.

To start out this unit, I first introduced the fact that

a force has both magnitude and direction.

I started out by holding a book up in front of me, then quickly letting go and catching it again lower down.

Question:  Why does it fall?
Answer: Gravity.
Question: Gravity is doing what to the book?
Answer: pulling it down.

Okay, so now we know that there is a force of gravity with some magnitude in the direction towards the ground.

Now the book is placed on a table.

Question: Is there still gravity on this book?

I got some weird looks with that.   . . . . . No?  . . .  Yes? . . . . I don't really know, but I think so, but it's not moving down. . . .?????

When the kids say "no," my eyes get real big and I say, "What?? There is no gravity anymore??"  And the kids say "okay, yeah, there is."

Question:  Then why is the book not falling down?
Answer: Because the table is in the way.

Oh!

Introduce this image on the smart board:

So we know there's gravity pulling it down. (Draw downward arrow).  But the book isn't falling through the table, so the table must be pushing up on the book. (Draw upward arrow).

HuUh??!?

Yes.  The table is pushing up on the book.  At this point you take the book back into your hands.

Question: Am I holding the book up with a force?
Answer: Yes.
Question: Then doesn't it make sense that the table also has to hold the book up with a force?
Answer: I guess so.

Then you do a whole bunch of other examples demonstrating the forces and which direction they are going. Examples can be cars, balloons, something falling (this was done to introduce the idea of air resistance), other things sitting motionless.

Now you introduce the idea that you can combine forces to find a net force.

SCENARIO 1

Here's a wonderful little picture analogy.  I chose a girl in the class to be the first person.  Sammy* (*names has been changed) is driving along the road when suddenly she runs out of gas.  She gets out and sees a gas station at the end of the road so tries to push her car.  But the car is too heavy for her to push and it won't budge.  She calls her friend (motion to Sammy for her to give her desired friend's name), Brittany*.  Brittany comes and tries to help, but they are both still not strong enough to push the car.  They then call a third friend (motion again for them to choose a third comrade) who comes and they all push with all their might.  They're finally able to get the car rolling.

Truth:

Students are more likely to listen when you use their name for an analogy.

Kids can easily see that because there are three people there is more force and the car will move.

Do lots of examples like this where you practice adding the forces, stressing that the forces are all going the same direction so you can add them.  Your answer must have both magnitude and direction.  I don't want "24N".  I want "24N ->"

SCENARIO 2

Tug-of-War.  Who doesn't love a good tug-of-war?

Team A is pulling with a combined force of 20N <-- to the left.  Team B is pulling with a combined force of 30N --> to the right.  

Question: Are the teams pulling in the same direction, or in the opposite direction?

Answer: Opposite direction.

Question: So do you think we're going to add their forces or subtract their forces?

Answer: subtract.

The net force is 10N --> to the right. 

Question: Why is the rope going to the right?

 .. . . pause while students try to figure this out . . 

timid student answer: because the team on the right is stronger?

YAY!  (remember that this is SPED, so kids need time to process answers). 

More tug-of-war examples with net forces to the right, to the left, and a net force of 0.

More examples like this on the board where both I model and the kids practice as a group:

Remember, the answer is 4N -->, not just 4N.

Independent Practice

Disclaimer, this is not my worksheet.  I found this fabulous worksheet online that I thought was just perfect for what we were doing.  I don't remember what website I got it off of, but it was one of those great teaching resource websites with free worksheets.  

To get worksheet, click here.

I printed the first two pages double sided for this day.  I printed pages 3-4 for another day to keep up practice.

Orienteering

New Mexico Grade 8 Science Standard I (Physical Science):  5-8 Benchmark III.
 #6:  Know that the Earth has a magnetic field.

This could be a 2-minute lecture on the earth having a magnetic field.  But when it's the last day before spring break, why not make it an entire 90-minute class period?

Welcome to Orienteering 101!

I handed out the little compasses to each student and we practiced learning how to use them.  Always remember that North is with North.  Then find your direction.  

I then took the class outside to the baseball field. I had closed it off to everyone else with big signs, and during my prep period (there have been many times I’m grateful that prep is first for me) I set up the orienteering course.  It took me about an hour to get everything set right, and then the rest of the period to perfect it and get everything ready

 

My first class did awesome.  They were in groups of two and each had a different course to take.  There were 8 markers around the field.  They got their first clue from me in the center, and then went off in the direction of their clue.  There they would find a new clue for their group that would send them in a different direction to another marker.  The first group back to me with all of their markers in the correct order won and got a prize.  It was fun, because the first group back actually didn’t have their markers in the correct order, so I sent them back at their second marker where they had first messed up.  They ran back.  I had a couple other groups come back with answers really close, but had 1 or 2 wrong.  In the end, we had a winner.  There were only 15 minutes of class left when everyone had finished (of a 90 minute class), and it being the last day of the week I told them they could do whatever.  Some joined the PE class on the next field in playing soccer.  Other sat in the shade of the dug-out.  I went around and made sure all of my clues were at the right markers and then sat in the dug-out with my class.  

My second class came in and didn’t do as well.  They could not figure out that North had to go with North.  They were trying to get the needle in the compass to move instead of physically changing the direction of the compass to match the needle.  I still had a winning group, but it was harder with this group.  I think it’s a combination that I missed a step in my introduction and that this groups had a higher percentage of lower abilities than my last class.  Also, it was much hotter this time.  But we only had to do this for half the class because this class had finally earned their class party.  After the winner came in, I gathered them all up and we went back inside.  They were good enough to help me pick up the markers and take down the signs before we left, though.  Then they sat in my classroom for the party where they ate chips that they brought and listened to music.  It was pretty chill.  But it worked.  :)

An example marker.  The Marker paper should be under the rock.  This is what happens after kids have been by. 

Magnetism

This will be a worthwhile post.   I'll not only tell you how to do cool experiments with your kiddos, but how to get your very own iron filings for free.

Hear that?  FREE Iron Filings!

When you have iron filings you can do cool experiments like this with the kiddos:

Pretty Magnetic Field Lines

I cut the corners of a piece of paper and folded them up to make a tray.  That way the iron filings wouldn't go everywhere.

I wish I could have let the kids try this on their own, but I don't trust them enough––I can see iron filings going everywhere and kids accidentally breathing in too much iron and then dying.  Not the best situation you want to be in as a teacher.

So instead we did a demonstration where they all stood around one table and watched.  It was cool and I the kids really liked it.  They also all asked me if they could do it themselves.  Since I don't want anyone dying, I said no.

Now for the part you've all been waiting for: How to get your very own iron-filings for free.


Method #1: 
Grab an old iron or steel nail and file it down with a heavy-duty file (not the wimpy kind you file your nails with, but a "manly file," as my husband called it.)  File down the nail.

I actually did this method for an hour during my Saturday afternoon.  I didn't get very much iron.  There was a small lump, and I could do some things with it, but you really don't get very much.



Method #2:
Place a magnet in a plastic bag.  Go outside. Rub the plastic bag in the dirt.  Lift and shake. There should be iron on the outside of the bag, attracted to the magnet.  Put this in a cup and take the magnet out of the bag to release the iron into the cup.  Tadaa!!  Repeat, repeat, repeat, repeat.

Depending on how much you want, this can also take a while.  The ASL interpreter in my first class told me about this, so during lunch I went out for ~5 minutes and just played in the dirt collecting iron.  It was awesome.  I got enough for our little demonstration above for my next class.

My little collection of iron filings from 5 minutes of Method #2.

I did also collect some dirt with this method.  So I took my dirty iron mixture and purified it even more by moving it from the cup to the final container using the same magnet-in-a-bag technique.  That lessened the amount of dirt quite a bit.  I used this second separation in my demonstration.

Method 2 would be a fun activity to do with your kids, too.  Make them go out and collect

real, natural iron from the EARTH!!!

and then use it to learn more about magnets.  (This could also go with any mixture separation lesson plans you may be doing.)

Yay for magnets.

Electricity Quiz

Electricity has been a really short unit.  My kids have enjoyed it.  I don't know if they fully understand the concept of electricity, but they know series and parallel and whether or not the light bulb is receiving electricity or not.  That good, right???

We're going to do a final review day.  We're going over all of the concepts and then they'll take this little quiz that they can use their notes on.  At the end, we'll also do a little review on our light/sound unit for those who want to retake the test next week.  If there's time we'll start learning about magnetism!  ooooh.  Exciting.

I hope it goes well.  I have had a lot of problems with behavior recently, resulting in one of my students being place in ISS (in-school suspension).  One other student probably also should have been place in ISS, but hasn't been.  We'll see what happens tomorrow.  So because of all of the problems, I'm not quite sure if the kids got all of these concepts like they should have.  Well, we're going to review and then I'll see how they do.

Here's the quiz.  It's meant to be printed double sided and cut in half.

Here are the quiz answers

Series or Parallel Circuits

This should have gone before my last post, but I'm not going to worry about it.  There are too many papers on my desk to worry about any kind of order in my life!!

Occasionally I try to organize my desk.

Occasionally the occasional organization project is actually successful.

So we can't expect my blog to be that much more organized!

Okay, here is the worksheet I had for my series and parallel class.  Our lesson was to be able to tell the difference between the two (series has one path for the electricity to flow, whereas parallel has two or more paths).  We went through multiple examples where the students had to show with their fingers how many paths there were.  Once everyone had the correct number of fingers, I asked them if that made it series or parallel.

We also had to be able to tell if the light bulbs would turn on.  If one is broken, what happens to the others?  If switch A is open, but switch B is closed, which light bulbs are on and which are off?

Lots of fun.

I like this kind of stuff because my mind loves puzzles.

Electric Circuits

On of the great memories I have from middle school science is learning about electric circuits. We would go to the lab room and get to fiddle around with all of the wires, batteries, light-bulbs, and whatever else there was at our disposal.  I knew when I got to this unit, that I would have to let my kids enjoy the same experimental freedom.  There is more power in doing the science than in reading about it.

For this unit, I always have a little lesson at the beginning, then sometimes a little worksheet to make sure they are understanding.  Afterwards, they have their little experiment they have to do.  If they are done, I let them play around with the materials before the end of class.

Oooh . . Science!
Apologies for my lame phone picture quality

We have done the following experiments:

1. Conductors and Insulators –DAY 1
2. Build a simple circuit –DAY 2

• Materials:
• A battery (no battery holders), 
• A free light bulb, 
• simple wires (no alligator clips) 
• Make the light bulb turn on, then draw your circuit and label the following:
• Conductor
• Insulator
• Power Source
• Light Bulb 
• (the gen-ed classes labeled this as "resistor."  I did not worry about that term with my kids. I wanted them to focus on "conductor" and "insulator" and understanding how a circuit works.)

3. Build a working series circuit –DAY 3

    Build a working parallel circuit –DAY 3

• Materials:
• 2 batteries (with battery holders)
• 2 light bulbs
• wires (with alligator clips)
• 1 switch
• Make the light bulbs turn on, then draw your circuits and label the following in each circuit
• Conductor
• Insulator
• Power Source
• Light Bulb **see note above
• Switch

5. Exploration with series and parallel circuits –DAY 4

• The lesson I had at the beginning of this class was two fold: review series and parallel circuits and practice drawing circuits correctly using symbols.  We used the mini white boards for this lesson so each kid could practice drawing the circuit instead of just watching me draw it. 

• For this experiment I wanted them to continue solidifying series and parallel circuits and to play around with the variables in a circuit.  How do you get a light bulb brighter? What happens when you have a lot of wires?  I had them follow this worksheet to get going.  The kids could go at their own pace on this one, which is what I loved about it.  For those who finished fast, I had a challenge circuit for them to build for extra credit.  

Conductors and Insulators

There isn't very much time to teach electricity.  Maybe 2-3 weeks?  So there are only a few points I want my sped kids to master: (1) conductors and insulators, (2) will the circuit work?, and (3) series and parallel circuits.  Today we briefly went over simple examples of which circuits will and won't work. The second half of the class was their experiment.  Excuse the dirty whiteboard.  I clean it, but it's an old board that isn't very good quality, so it doesn't stay clean for long.  The kids were to copy this format on a sheet of paper.  Once they and another person were done, they grouped up and completed the experiment together.  I had a few objects set up for them to choose from, but I wanted them to look around for themselves.

I wrote this up really fast, since I only have this one little whiteboard in my room and I had used it previously for two other things that day.  So the definitions are not perfect, but they work.  

Translation:

Conductors and Insulators Experiment

1. A conductor will allow electricity to flow. 

2. An insulator will not allow electricity to flow.

Find 10 conductors and 10 insulators.

(table numbered 1 - 10)

They did really well.  I was impressed with which things the kids thought to test. I had kids taking random things out of their bags to test, I had kids carrying their set up to the door handle or the sharpener that's bolted to the wall.  It was pretty good. And they had fun with it, too. 

Simple circuit. Light works. 

Simple circuit with metal scissors conducting electricity. 

Simple circuit that doesn't work.  The plastic is an insulator. 

This is the little Electricity kits I had in the classroom.

There were three kits, so I had three groups of 2 or 3 kids.  Some kids also got into it and built more complex circuits and then tried their object to see if it would conduct electricity or not.

Today was mostly an exploring day.  I could have just told the kids that metals are conductors and basically everything else is an insulator.  But sometimes, you just need to explore it for yourself.  It makes it easier to remember, and these will be the classes they remember most.

Electric Circuits!

Once you teach the kid about electric charge (positive and negative charges), and after they understand that opposites attract, then you can introduce the circuit.

Basically,

the electrons (-) are racing through the circuit trying to reach the positive (+). This creates electricity. 

I discovered this great online tool that I'm going to use in class tomorrow.  I wish I could introduce the subject and have them all work and discover this on their own computers.  However, that is not possible.  I have one computer in my classroom open for student use.  So far I have found no reason to have one student on the computer while all of the others are doing something else.  So I'll have this up on the screen, we'll do it together, and they'll fill out their guided notes. 

Here's the AWESOME online tool!

Guided Notes Page 1

Guided Notes Page 2

Guided Notes Page 3

The Quiz:

Quiz Page 1

Quiz Page 2