Why Are Astronauts Weightless?

Continue on...this is not the end of the homework page...

Homework:
Review Chapter 3, the beginning which you read last homework period (pages 75-79) and continue to the end of section 3.2 - reading carefully the parts "Projectile Motion" and "Centripetal Force".   Do the "Try at home mini-lab on page 81. In your lab notebook, describe the experiment and answer the 3 Analysis questions.
Answer the Section 2 assessment questions, as well as the reading guide questions (handout from class).

And here are some fascinating videos to go along with our studies of motion:
What is a force?

What forces are acting on you?

misconceptions about falling objects

Why are astronauts "weightless?"

 

Why are astronauts "weightless?"

continuing with MT science...

Now that your ideas about how to build a mousetrap car are becoming clearer,  RE-read the handout on the Physics of Mousetrap Cars. Write more notes at the bottom of the page, saying how you can build your car better for speed, distance and so on.  

If you did not turn in the F=ma page, do it now.  Link is in the previous post.  If you did not watch those videos, please do so.  There were too many blank faces on Monday.  I'm hoping for some light bulbs.  >>>  ANSWER THIS QUESTION IN THE COMMENTS BELOW:  In your own words and as succinctly as possible, what does "F=ma" mean?

A Question to Ponder: What does gravity have to do with F=ma?  We will explore this question on Thursday, and will work on our MTcars when we get back to the big room at the church.  Read your textbook Chapter 3.section 2, but only pages 75-78, Gravity.

 and two more short Eureka videos, AFTER you read the textbook! >>>

Force, Mass and Acceleration...it's a Relationship xoxox

Here is the homework which I inadvertently  neglected to publish last Monday, so we will do it now.  My goal for you is that you understand this Second law so well that you will incorporate it into your mousetrap designs.  We will continue designing and building on Monday in class.  I will require you to have a written plan before you cut wood, including measurements,  seen by me.

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Thanks for class today; hope you enjoyed the art lesson.  Keep working on your designs, add measurements (how long are the side rails, how long the bed, what is the radius of the front/back wheels) and make it as accurate as possible.  Keep thinking about how to reduce mass and friction.  I will need to approve your plans before you cut.

Derek Owens, Video Tutor:  This is particulary important for the 7-9th grade students to watch, in order to understand Newton's second law at your grade level, including how to use it in an equation.  It is very good teaching, but unlike Bill Nye, it is neither funny, cute or annoying.  Probably much to your relief.  Watch the 2.3 segments numbered  2.3a-2.3f  It takes  about 30 minutes total in 6 segments, so break it up if you need to, and TAKE NOTES--pencils are the best brain-makers.  Younger students: this may or may not be difficult, but try anyway, and let me know how it goes>>>I want to test your limits!

Go here for the chapter 2 playlist, but be sure to watch only sections  2.3a through 2.3f:

 http://www.youtube.com/watch?v=Kc3TIJPe38k&list=PLWkr0FoP_-fS47nEZ7mJqXo9a7MoxeDJi&index=17   

or  else try here and watch continuously till you've finished all the way till 2.3f:    

   

I handed out a F=ma worksheet in class for you to  solve the problems.  Ask your parents or siblings for help if you need it.  Turn in on Thursday!!!  Using a calculator is fine, but follow my directions, and SHOW YOUR WORK.  -  -Write the formula you will use -- plug in the numbers with the units -- solve -- draw a diagram like Mr. Owens did in the videos.  The first problem is done as a demonstration of what I am looking for.  Here is a copy if you've already lost the one from class: http://www.nhvweb.net/NHhs/Science/gcollins/CP%20Physics%20Assignments/Newton's%20Laws/F=ma%20Worksheet%20A.pdf

You should already have read in your textbook Chapter 3, section one, which discusses friction as well as Newton's 2nd Law.  Read it again for review, and it should make lots of sense by now.

Lastly, some experimental stuff from TOPS to do at home -- find the "cards" 17, 18 and 19, cut out and glue in your lab books as discussed in class.  Build An Accelorometer (card 17) Acceleration Is Change (18) and if you have time and like puzzles, try Seconds Per Second (19), which is very challenging but optional.  Cards 17& 18 require a small jar; doesn't have to be a baby food jar--any  glass jar with lid should work fine. Keep the accelerometer for a while and get to know it.  :)  Like I said >>>  F=ma, it's a relationship.

MT Monday!

Important! We will start on our Mousetrap cars on Monday, and unlike yesterday, we will not hurry through it (yay!) So collect CD's with your mom's permission; if you are like my family there are probably a few around the house that are not important from years ago when we bought "educational" things that no one wants anymore. Recycle some toy wheels, bring in something lightweight to build with or just to try out...use your creativity.  I will have most of the basics, but feel free to add to the collection.

Homework:  Give some thought to the explorations in yesterday's class (re-read the cards carefully) , and answer any questions you might have missed in your lab notebook.

2. Finish reading the Mousetrap handout: write notes in the empty space at the bottom of the pages to comment on how to make your car go - faster - further - decrease friction - increase traction - reduce air resistance - decrease mass - and whatever to make it the best it can be!  I suggest that you might pay better attention to what you read if you read it aloud; it works for me when I have to read things that are complicated.

When we finish building we will take them to the park for some races. (Hopefully the tennis courts will be available.)

3. Here is some great old-time science, from Julius Sumner Miller, a review on Inertia which I think you will enjoy, in 2 parts. 15 minutes.  He cracks me up.


P.S. Does anyone have a broken laser pointer they would like to give me?

The topic of our text today is F.R.I.C.T.I.O.N --

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Remember with a pencil - take notes!

And if you are not too sophisticated, Bill can't be beat for crazy science explanations.  Still good to take notes.  Watch until it gets truly annoying, which is after 10 minutes or so.  But you can watch it all if you want.

For reading you have the mousetrap car basics which was handed out in class;  remember to take notes on the blank portion at the bottom of each page, listing science vocabulary and ideas for making your MT car faster, stronger, better for distance, reducing friction, increasing traction, and so on.  Read about half of the handout.  AND THENNN...

Read the textbook, Chapter 3, section 1.