Class 4

Greetings, Parents and Students.  Keep up the good work!!  In Class 4 we are going to go into the practical uses of vectors.  We'll also do a short but educational play with two student actors!

First, I want to outline a way for every student to improve their homework understanding and grades.  How do you know if your answer is right?  Many people don't worry about that, or they do the problem again to see if they get the same answer.  Neither way is very good.  If you repeat the problem, you may have the same misunderstanding or make the same error again, so repeating does not tell you if you are right.

^{I have prepared a carrying card for you that outlines three good ways to check your work.  If you use any of them and get the same answer, your confidence in being right should go way up. You'll be surprised at how much fun checking is.  Click this link:
https://sites.google.com/site/yhbscience/Class4.Carrying.Card.for.Checking.Problems.docx?attredirects=0&d=1}

A QUESTION:  A parent asked me how we measure the vector angle.  We start the angle at the x-axis and swing around counterclockwise until we reach the vector.  Assuming that the x-axis direction is east (E), we would get the following angles (in degrees): E = 0, NE = 45, N = 90, NW = 135, W = 180, and so on.  By the time we get around almost full circle, we have SE = 315 and E = 360 (or 0 again).  Sometimes, to avoid large angular numbers, we start at the x-axis and go clockwise, but change the sign of the angle!  Sometimes pocket calculators do this.  This gives: E = 0, SE = -45, S = -90, SW = -135, etc.

NOTE - To make matters more "interesting," sailors and pilots don't do it like scientists and mathematicians. They start at N and go clockwise !!  Oh me, oh my!

Here's Homework 4.  Best wishes!  Please don't forget to bring it to class.

https://sites.google.com/site/yhbscience/Class4.Homework4--Summary.of.Classes.1.to.4.docx?attredirects=0&d=1

UPDATE: 1/30  8:15 AM  If you see this in time, please bring to class.  If not, I will have extra copies.

https://sites.google.com/site/yhbscience/Class4.Handout--Units.of.Physics.docx?attredirects=0&d=1

UPDATE: 1/30 1:00 PM  I know this is too late to bring to class.  Please make sure you download it.
https://sites.google.com/site/yhbscience/Class4.Handout--Solve.any.vector.problem.docx?attredirects=0&d=1

Class 3

Hi, Students!  Keep up the good work!  You're making progress with a new and difficult subject! Check the bottom for homework and any other handouts.

WED 2 PM***PARENTS -PLEASE CHECK YOUR EMAIL FOR HELP ON HOMEWORK 2**

THU 1 PM***For help with questions 3., 4., and 5. in next weeks Homework 3 (Class 3 - Handout 3A-- click below) you should use GOOGLE.  EXAMPLE:  Question 3: try Googling something like "names of planets."

Here is the link to the ARCTAN calculator.  Remember, O is "theta", the angle you want!
Go to  http://calculator.tutorvista.com/arctan-calculator.html    to get the program.

To get the angle, O, in degrees, put the value you get for Ry/Rx into the ARCTAN calculator.

NOTE - there is a problem in ARCTAN when Rx or Ry or both are NEGATIVE NUMBERS.  You MAY get the answer pointing exactly in the opposite direction from the correct answer.  If this happens, just add 180 degrees to the angle in the calculator, and you should be right.
EXAMPLE: You get -20 degrees (and you see it should go in the opposite  direction), you add 180 and now have 160 degrees (-20 + 180 = 180 - 20 = 160).  Now you see everything lines up right. 

From now on in this blog, we'll use   \/X\   =  square-root of X    and    X2 = X squared

Want to find the magnitude of a vector, like R?  The magnitude of R is R.  To get it use:
           R  =   \/(Rx2  +  Ry2)\   (First do squares, then add them, then take square-root)

So, the vector equation  R = Rx + Ry is RIGHT, but the scalar eq'n  R = Rx +Ry is WRONG.
( To make it right, you need to use the squares and square-root!!)
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EXAMPLE:    Find R and O, if  Rx = 5, and Ry =12 [can write as:  (Rx, Ry) = (5, 12) ]

1) FIND R:     R =  \/(52  +  122)\  =   \/(25 + 144)\  = \/169\ = 13     So,  R  = 13

2) FIND O:    O = ARCTAN(Ry/Rx) = ARCTAN(12/5) = ARCTAN(2.4)
Putting 2.4 into ARCTAN calculator get 67.38 degrees.       So,  O  = 67.38 degrees
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BASIC EQUATIONS TO GET R and O if you know Rx and Ry !      

                   R  =  \/(Rx2 + Ry2)\         <==  Don't forget square and square-root parts
                   O  =  ARCTAN(Ry/Rx)        <==  Ry comes first
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  Hope everything works for you!

Mr. Frank

https://sites.google.com/site/yhbscience/Class3.Handout3A--Homework.Vectors.and.the.Universe.docx?attredirects=0&d=1

Class 2

Note to Parents:

Hi, everyone!  I hope your children taking my Physical Science course at YHB are learning something about physics AND having fun as well!  That is my goal.

I have never taught ten to sixteen year olds before and still am learning what they understand.  Please make sure they know that I will be adjusting things as necessary.  If they work hard, I hope everyone will do fine.

I also think I use a lot of words they don't know, so please help them when needed (I am not talking about strange physics words, like momentum or torque  -- I define those in class as needed.).

It would help the children a LOT if they can read Handout 2B before class and at least take a look at 2A.  If you don't see this in time -- that's OK   :)    .

Thanks a lot, and please let me know if you have any questions or comments.

Blessings,

"Mr. Frank"


https://sites.google.com/site/yhbscience/Class2.Handout2A--Homework.Scalars.and.Vectors.docx?attredirects=0&d=1

https://sites.google.com/site/yhbscience/Class2.Handout2B--Scalars.and.Vectors.docx?attredirects=0&d=1

First Post

To:  Physical Science Class at YHB
From:  Mr. Frank

I am trying to create a blog where my students can receive notices and attachments (like assignments).

Let's see what happens!

MrF

OH GOOD, IT WORKS!

https://sites.google.com/site/yhbscience/Class1.Handout1A.docx?attredirects=0&d=1

https://sites.google.com/site/yhbscience/Class1.Handout1B.docx?attredirects=0&d=1

https://sites.google.com/site/yhbscience/Class1.Handout1C--InstructorsORBITS.docx?attredirects=0&d=1

https://sites.google.com/site/yhbscience/Class1.Handout1D--ORBIT.RECORD.SHEET.docx?attredirects=0&d=1

https://sites.google.com/site/yhbscience/Triangle.Challenge.docx?attredirects=0&d=1

https://sites.google.com/site/yhbscience/Homework.Assigments.Cards.docx?attredirects=0&d=1