Paul Caginalp
Science	Grade 8
Regular	4/5-end

Newton, Fluids, and Pressures

 

Abstract: The unit starts with Newton’s laws of motion, and proceeds into pressure and fluids.  The students have been doing a lot with forces and motion already, so much of Newton’s laws will draw from their prior knowledge.  The major thing the students will have to do in this unit is apply demonstrations to the things they are learning.  The second quiz will include a demonstration that they will have to analyze.  It won’t be as tough as some of the ones I do in class for them, but it will take a knowledge of air pressure.  The end result of this unit will be that students see science in the world around them.

 

 

 

Essential questions:

How can the exploration of science make us more able people?

What are the misconceptions that we hold to be true in science?

 

 

Unit questions:

Can we ever have an object in constant motion?

What action moves a space shuttle into space, and in space?

Is there air pressure, how strong is it, and why don’t we feel it?

Why don’t we ask deer to fire guns instead of shooting them ourselves?

How does an airplane wing work?

How do hydraulics work?

If steel doesn’t float, why does a battleship float?

 

Topic list:

Newton’s First Law

Newton’s Second Law

Newton’s Third Law

Pressure

            Air

Fluids

            Bernoulli’s principle

            Pascal’s principle

            Buoyancy

 

Vocabulary Words:

Outside Force: a force from outside of the system or reference frame

Reactionary force: The equal and opposite force of a force pair

Pressure: force per area

Fluids: any substance that molds itself to a container

Hydraulics: any system that uses a non compressible liquid to transfer pressure

 

Key Activities:

Demo quick writes- I want the students to take what they see, apply the science they are learning, and come out with a reason.  I don’t even care all that much about the right answer as long as they have a reasonable explanation.

Tarzan Homeworks- Tarzan the haphazard jungle explorer finds himself in all sorts of troubled situations where he needs the students to find out if his vine is going to break over the alligator pit or not.  My hope is that the questions will be a little more exciting than basic questions without my unlucky explorer.  

2 quizzes

Labs – I am going to have the students do a few in class labs on force, and aerodynamics.

Spotlight on a scientist- I am going to make the scientist to be more than a name and an equation through interesting and weird facts about the persons life.  I am asking them to do the third one, which is on Blaise Pascal, a thoroughly strange individual.

 

Pieces of the real world:

Hydraulic systems like car brakes.

Airplane flight/lift.

How steel battleships float.

Rocket engines push down, not push down on the ground.

 

Big Ideas:

The big ideas for this unit are how all these ideas that they are learning tie into their lives.  Newton’s Laws tie in fairly well, with the exception of law 2, so that will be fairly easy.  For the law of inertia I am going to also include ideas about what is possible on earth, and what isn’t.  An object moving indefinitely on earth is not possible, but I expect the students to realize that it is possible in space.  For the third law I want them to be able to identify action reaction pairs.  I want the students to understand that the accelerated turning of wheels on a car is the force pair of the car’s forward motion, not the force pair of the frictional force between the wheels and the road.  That is one example of a common misunderstood force pair.  For pressure I want to show how much air pressure can really do, as well as the properties of pressure.  The properties of pressure that I want to show are that it flows from high pressure to low pressure, hot air is lower density, and how strong it can be.  For fluids, I am showing three properties of fluids, as well as making the distinction of English language fluids vs. science language fluids.  The three properties I will show are the Bernoulli principle, the Pascal principle, and buoyancy.  Bernoulli shows why airplanes fly, Pascal shows principles of hydraulics and buoyancy explains why really heavy things float.  

 

Standards and objectives:

Mr. Lake gave me standards for the lesson, which were to include Newton’s Laws, the three properties of fluids, and pressure.

 

The objectives I have picked are:

Students will be able to use Newton’s laws to explain motion.

Students will be able to identify action reaction pairs.

Students will be able to identify the action going on in a demonstration

Students will be able to tell me how an airplane flies, how hydraulics work, and why battleships float.

 

Central question and concept map:

How can the exploration of science make us more able people?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Assessment: 

            The major assessment for this unit is going to be the quick writes that the students do on the demos I present.  I will be presenting at least five demos which the students can use to gain practice doing demo quick writes.  The last test of their ability will be on the second quiz, and will be graded.  All the ones before will be either practice or worth a homework grade.  I am not looking so much for accuracy at describing what went on.  Even I cannot get good accuracy looking at a  demo for the first time and describing it.  What I am looking for is the application of what we have been doing, and the logical thought process.  The kids can tell me that a giant hippogriff snuck in behind me, and shoved the egg in the bottle while I wasn’t looking if they have the evidence to back it up (which I sincerely doubt).  Learning cycle application: I plan to do the first one for them, and show them the thought process that I want, as well as the application of class content that I want.  The next few will be done with a quick write after them, then I will go over it with student input.  These will not count towards their grade.  As we get to the 3^rd or 4^th one I will start counting them towards homework grades, and finally there will be one graded on the quiz. 

            The other major assessment in the unit will be the homeworks that the kids hand in.  I will take the best 4/6 assignments for their final grade.  The homeworks will vary from working problems to explaining an application of the theory taught in class.  The third law homework for instance will have pictures of various objects in motion, or of various actions, and the students will have to come up with the reaction pair.  There will definitely be more than one right answer for each problem in this homework.  With this form of assessment I am looking to catch misconceptions early and to look for understanding on a nearly daily basis. 

            The final assessment in the unit will come from the two quizzes and a possible take home test which I am currently debating with myself.  The two quizzes will have questions similar to the homeworks, or other problems done in class.  One will have a demo quick write on it.  They will be single period quizzes looking mainly for explanations of phenomena.  The test, if I choose to give it, will be open notes, open to working in groups, but no internet and no parent assistance (I hope).  The only parent assistance I would agree to would be parents reading the problem to the child.  It would be two questions, of which the students would choose one, and write an explanation of the forces involved, the action reaction pairs, and further explanations that would be problem specific. 

Class day	Topic list	Vocab	Demos	Lab	Activities	HW
1	Newton’s Law 1: An object at rest will stay at rest, an object in motion will stay in motion unless acted upon by an outside force	Friction (review) Outside force	Friction cart at rest, friction cart in motion.   Bouncy ball at rest, bouncy ball in motion.		Do 1st of HW in class   QOD: Is there a place on earth where the law is true?   Spotlight on Newton	Wkst: which is the outside force?
2	Newton’s Law 2: F=ma	Force (review) Acceleration (review) Mass (review)	Water bag and ping pong ball	Calculate force of air resistance on puck, and of the rubber band.	Derive F=ma with the kids.   Show how to use equation (units)   QOD:  how can we tell how much force we use?  (20 questions)	Wkst: Tarzan/alligator/Babe Ruth/car + mailbox
3	Newton’s Law 3: For every action there is an equal and opposite reaction.	Reactionary force	Kids on skateboards (have kids bring in skateboards)   Balloons		Discussion: space shuttles   QOD: How does the space shuttle move?	Wkst: Tarzan/force pairs (tarzan is last question)
4	Quiz
5	Pressure	Pressure Fluids	Egg in a bottle   Cup and note card		Brainstorming activity: air pressure   QOD: What property of air affects us every day but is rarely noticed?	Wkst: In what ways did you use air pressure today?   Why don’t we have deer shoot guns for us? Closure?
6	Bernoulli’s principle		Blowing on top of paper   Come together   Floating ping pong ball	Paper airplane distance contest	Airplane wing   QOD: How do airplane wings work?   Spotlight Bernoulli	Finish writing up lab.
7	Pascal’s principle	Hydraulics	Garbage bag blow up?   (pressure in system must be consistent, so a little pressure goes a long way)		QOD: How do your car brakes work?	Spotlight on Blaise Pascal
8	Buoyancy	Volume (review)	Block of aluminum foil vs opened aluminum foil.		QOD: Why do battleships float	Why do submarines float, and sink?
9	Quiz				Can crusher

Selected Plans:

Day 1- Newon’s first Law of motion

            I will start with the bouncy ball to get attention.  I will drop it to the floor, and ask for observations.  After collecting a few about the ball bouncing lower and lower each time, and eventually coming to rest, I will give Newton’s first law.  I will then ask if it makes sense.  I want the students to look at it in three pieces.  The first piece is that an object at rest will stay at rest.  The second piece is that an object in motion will stay in motion.  The third piece is that the two previous pieces will happen unless acted upon by an outside force.  I want to work the bouncy ball demo into the discussion by having the students figure out what the outside force is (gravity) and make sure that it holds true for the friction cart as well.  I will then work into the question of the day.  After the question of the day, I want to look at the HW and do the first one, as the class winds down.  For my closure activity I want to do the spotlight on a scientist activity which will be Newton for the day.  I have a few anecdotes prepared on his absent mindedness and on how weird he was.  I am going to save the water bag and ball demo till the next day as my bell ringer, and my review.

    

Foreshadowing, Introduction
I plan to put the agenda on the board, and let a racket ball drop a few times as an attention getter	Filing in, getting out their notes, and shifting into class mode.
Activities of the lesson
The big activities of the lesson are the demos, so that the law makes sense and the question of the day, which I hope to make a good group discussion.  I think it will challenge them slightly.  The spotlight on a scientist is of lesser concern to me, except that I want them to do one later, so I am modeling it now.	They will be taking notes on Newton’s first law for some of the time, but mainly they will be discussing I hope.  Newton’s first law is so logical, but so strange that I need them to be willing to think about it more than anything else.
Reflection, Summary, Conclusion
I will be doing the spotlight on a scientist as a closure activity to give them a little extra information that they might not otherwise search out, and to give them a point of interest to start from if they ever wanted to look up a scientist.  I am also doing it so they can do it later during Pascal’s principle.  Homework will also be handed out, and we are going to do the first one together.  The homework will be dealing with outside forces, and how they are affecting the object in the problem.	They will be doing the first question of the homework, but then they will be packing up, and having a little time to just relax and listen to some information they might find interesting at the end of a really thoughtful lesson (I hope).

 

Day 3-Newton’s third law of motion

            For this day I plan to start off with my question of the day as the introduction.  As far as I have seen in the classes, I expect the students to say initially that the rocket booster shoots out flames, and those flames push on the ground, and the shuttle is moved upward.  I expect them to next argue that the flames push on the air molecules when it moves too high for the flames to touch the ground, and I plan to get closer to the real answer when they realize that there are no air molecules in space.  From this example I want to move into Newton’s third law which is that for every action there is an equal and opposite reaction.  From here, I want to move to a demonstration.  I will have asked the students to bring in skateboards.  I want two students to sit on the skateboards facing each other, and push off.  The result I am looking for is that they pushed on each other, but both went backward.  A second demonstration I want to use is the force that balloons put out when blown up and released.  Kids always get a kick out of balloons, and most kids will say that the balloon moves because the gas is expelled out the back, which is true, but most won’t carry it through to the fact that the balloon is pushing inward on the air.  After moving through those two demos I want to do the first homework problem with the kids, and then let them start on their homework as the end of the lesson.

 

Foreshadowing, Introduction
The attention grabber as well as the introduction will be the question of the day.  I want the kids to answer it with very minimal guidance from me.  I want them to have to correct each other.  I will be cultivating this at other times, but will also be doing it here.	The students will be engaged in discussion about one of their favorite topics, and learning what I want them to at the same time.
Activities of the lesson
The activities for this lesson are the demos.  I want the students to extract as much as they can from the skateboard one, since it is a different type of example than the one in the question of the day.  The balloon is much closer to the question of the day example, so I will ask them to do a quick write on it.  This will most likely still be at the practice stage of the quick writes, as it will be the second one I ask them to do.	Students may participate in the demo, or they may watch it.  The ones watching it must watch it for the action and reaction, while the ones doing it will most likely be busy thinking about the action rather than the reaction.  After that the students will be doing a practice quick write, most likely still getting accustomed to the format.
Reflection, Summary, Conclusion
The closure of the unit will include doing one of the homework problems with them, and then letting them do the rest with their table members.	The students will be walked through one problem, and then be set loose to do as many as they can before the bell rings.

 

Day 5- Pressure

            I want to start the day with the question of the day.  The question of the day should get them thinking about air, and hopefully will lead to the idea of air pressure.  After the question of the day, I want to do a brainstorming time with the students.  I want the students to take 15 minutes, and come up with everything they can come up with on the subject of air pressure.  It will give me a good idea of what they know, what they think they know, and how far I have to go in the pressure area.  After the brainstorming unit I want to do the cup and index card demo, and then move into pressure laws like hot air expands to give more pressure, and is less dense, or that air flow occurs from high to low pressure.  After that I want to do the egg in a bottle demo, to show the high-low movement again.  This will be a quick write, and may be the first one I count depending on how the last one turned out.  Finally I want to start breaking away from air pressure and give a question to close class with.  The topic will most likely extend more than a day, but I want the question to carry over to the next day anyway.     

 

Foreshadowing, Introduction
I want to start with the question of the day to give a topic for the day, and a little bit of a shock to the students that they are constantly under all this pressure and they don’t feel it.	The students will be busy trying to figure out the answer to the question of the day, and then brainstorming in their tables their knowledge of air pressure.
Activities of the lesson
The demos will break up the notes nicely, so that students can stay focused, and the question at the end should provide for some interesting discussion.	Students will be doing a demo quick write, and some discussion as they wrestle with the fact that I can push one of them and say that they pushed me.
Reflection, Summary, Conclusion
For the closure I want to step away from air pressure, and give a question that will use their understanding of newton’s third law as well as making them look at the issue of area as related to pressure.	The students will be engaged in a question that seems logical without an understanding of what factors influence pressure.  Once they realize that area is a big part of pressure it becomes clear that the stock of a gun is preferable to the bullet.