Welcome to Physics NotesLevel 1: Getting StartedClass WebsiteThe class website is an extremely important resource in this course. Turn on a computer or use your phone to go to the site below:www.storyphysics.weebly.comYou may need to memorize this web address (most students do) because you will be visiting this site often. The following directions may vary depending on your phone or computer… At the top of the page, in the menu, you will see the word “Physics”. Scroll over this without clicking on it. The drop down menu will tell you the different unit names in physics (right now there is only one, but there will be more as we move on). Click on “Introduction to Physics” and move on the directions below.

Login to ProProfIn this class, we will frequently be using a program called ProProfs, which allows you to take online challenges and practice tests. You will be on this program at least once a week. This allows me to see how many times you’ve taken a quiz, which problems you struggled with and how long it took you to complete. You should be aware of a few things regarding ProProfs.

1. It flags you if you do the problem in an impossibly short period of time. You cannot just randomly click through and earn points. I check this and will not give you (or your group) credit if you do this.

2. It tells me if you have somebody else do your quiz. By tracking which computer you use to take these quizzes, the program lets me know if you are having someone else do your work. I will give everyone in your group a zero if you attempt to do this on challenges, and you a zero if you try to do this on practice quizzes.

3. It requires a username and password. I will be coming around shortly to give you your class id and password. Please keep track of this information.

Things to Do:Once you get your username and password, go to the class website (see above). Scroll over “Physics” in the menu at the top, wait for the drop down menu to appear, and then click on “Welcome to Physics”. There is a link there that will take you to ProProfs. Use the login and password I give you to make sure you can log in. If you can’t, please let me know the next time I am with your group.

RemindYou may have already used this app with your coaches. It allows me to send you texts about important class information. I will not be able to see your number or to text you individually. You won’t be able to text me at all and you won’t have my number. I won’t use this too often, but it can be helpful. For example, if we have a snow day when we were supposed to have an

exam, I might text you and tell you the test is moved so that you won’t stay up studying. Or I may remind you on Sunday about a major test if it happens to fall on a Monday. I will not fill your inbox with pictures of puppies or fascinating science articles. I will use this pretty infrequently.You can sign up one of two ways. Either works fine, just don’t do both:

The Subject of PhysicsPhysics is a branch of science that studies how things move. Car crashes, rocket launches, hockey games, gas particles, balloons, airplanes, suns, planets, moons… these are the things that physicists love to think about. Beautiful, objects in motion….all of them controlled by physics and math. We are curious how fast things are moving, how far they are likely to go, and what made them move in the first place.There are many different branches of physics. Some deal with liquids or gases gases. Physics explains where electricity comes from and why the sky is blue. In this class, we are going to spend most of our time on a particular branch of physics called mechanics. Mechanics is the study of how large, every day object move. We won’t talk a lot about molecules and protons (we’ll leave that to Chemisty and AP Physics 2) but we will talk about dancers, football players, race cars, space shuttles, and pirate ships. Physics will involve a lot of math- there is no way around it. I know this probably just made you groan and probably swear a little. Don’t worry too much about this right now. Physics is an acquired taste- some students love it right away, but most start the year out a little suspicious of the topic because there is a lot of math involved. By the end of the year, nearly all of my students tell me they like physics… it really is a likeable topic. It helps math make a lot of sense, even (especially) if you aren’t exactly a math-y person. Be patient and we will get you there.

Level 2: Scientific NotationBefore we can get started in physics, we do have to review a few things we learned in previous classes (sorry). We often use scientific notation in physics. Many of the objects we deal with

(planets, starts, mac trucks…) are huge, and we need numbers that can reflect that size. It is therefore important that you get comfortable with scientific notation (if you aren’t already).

Writing Numbers in Scientific NotationWe express numbers in scientific notation this way:

2.78×103

or….

4.0×10−4

The most important thing to remember when working with scientific notation is this:

If the exponent on the ten is greater than zero, it is a big number.6.01×108=6010000

If the exponent on the ten is less than zero, it is a small number.6.01×10−6=0.00000601

Let’s first practice putting large numbers in scientific notation. Watch me try one:Example Problem 1: Putting a Large Number in Scientific Notation

26000000

That is an annoying number to work with, so I put it in scientific notation. 1. Write the decimal after the very first number in the sequence (not a zero).

2 .6000000

That’s where you want the decimal to end up.2. Count the number of spaces you need to move the decimal.Right now, the decimal is invisible and hidden at the end of the number. Count the number of spaces you would have to move it to get to the place you put it in Step 1.

2 .6000000

I had to move the decimal seven spaces. Remember that number: 7.3. Put the number in the correct scientific notation format.

A .B×10x

Take a look at the number: 2.6000000. First, we hack off all the zeros at the end:2.6

Then we add the x 10.2.6 x10

Now, we put the exponent on the ten. The exponent we add is the number of spaces we moved in the last step.

2.6 x107

Is that a positive or negative 7? Well, look way back up at the original number. If the number is greater than 0, it is a positive 7 (in this case, it is). If it was smaller than 0, it is a negative number.

Turning Scientific Notation into NumbersThe basic format of scientific notation is:

A .B×10x

If that exponent on the 10 is greater than 0, it is going to be a larger number. Because we know it is going to be a big number, we need to add zeroes to the end. This makes more sense when you watch me do it.

3.5×105

The 5 is positive, so I know I’m going to need to make this into a big number by adding zeros at the end. How many. Well, I count the number of spaces I need to move the decimal- 5.

3.5

I moved it over to the right because I know I’m adding zeroes to the end. Now, I fill in those spaces with zeroes.

350000

That’s our answer. If the exponent is smaller than zero, it is going to be a small number. If we want to make a small number, we need to move the decimal to the left. Let’s try one together.

3.701×10− 4

We move the decimal four spaces to the left. 3.701

Then we fill the spaces in with zeroes.0003701

So the number is:0.0003701

Multiply and Dividing in Scientific NotationIn this class, you will always be allowed to use your calculator. This makes multiplying and dividing in scientific notation a lot easier. There are a few things you need to look out for, however.

1. Always, always, always put parenthesis around the number that is in scientific notation. This will help your calculator understand what you are looking for. For example:

1.7 x109×3.6 x 10−3

Should be entered into your calculator like this:( 1 . 7 x 10 ^ 9 ) x ( 3 . 6 x 10 ^ - 3 )

2. You calculator will sometimes give you the answer not in scientific notation. For example, in the problem above, my calculator told me the answer was 6120000. That’s still a big number. I need to put that in scientific notation. Therefore, my answer is:6120000 = 6.12 x 106

Stop! Before you move on to the next section, complete Level 2: Scientific Notation Practice (in your Practice Packet).

Level 3: ConversionsThis should also be a review from chemistry (again, sorry).

Standard UnitsIn physics, we will always, always want things to be in the metric system. Let’s talk about the difference between the way we typically measure in the US and the way we measure these in the metric system.What is Being Measured In Normal People Terms

(English Units)In Smart and Attractive People Terms (Metric System)

Time Years, Minutes, Hours, Seconds

Seconds (only seconds)s

Distance Miles, feet, inches Meters (only meters)m

Mass Pounds (this isn’t accurate, but what the hey…)

Kilogramkg

SecondsYou are already pretty familiar with these. In physics, we do like to keep everything in seconds, which can we weird. For example, we wouldn’t say you have 170 days of school left. We would say you have 1.46 x 107 seconds left. Sounds strange now, but it will make calculations easier later.MetersAsk me to bring around a meter stick, if you are curious about how long this is.KilogramsThis one is probably the hardest for students to grasp. A kilogram is larger than a pound, which means that the number is smaller (see below). I will bring around a kilogram for you to feel. A metal stapler has about 1 kg of mass.

That was confusing- here’s an example. Ms. Story’s Weight in Pounds Ms. Story’s Mass127 lbs. 57.6 kg Notice this number is smaller

We will later learn that weight and mass are not the same thing, but showing it to you this way can help you grasp it. I’ll explain the difference when we get to forces.

One Step ConversionsYou probably had to do this a bunch in chemistry. If you are already good at this, help your group mates catch up. Before we move on, we are going to need to make sure everyone can do conversions. To help you review, I want us to solve a problem together.Example Problem: One Step ConversionA roll of Christmas gift wrap contains 2.5 meters of paper. What is the length of the paper in yards? Remember that 1 meter=1.09 yards

SolutionStep 1: Write down the known values and the unknown values.

Known :  length of paper in meters: 2.5 meters    Unknown :     length of paper in yards

Step 2: Find the conversion factor that gives a ratio between meters and yards. This is almost always given to you in the problem or is in a conversion table you are given.

Conversion factor    1 meter = 1.09 yards

Step 3: Write down what you were given. This is what you are going to start with.2.5m

Step 4: Multiply by the conversion factor. Make sure that the units are kitty-corner from one another. If m is on top, you need meters to be on bottom in the conversion factor.

2.5m× 1.09 yrd1m

Step 5: Multiple what is on top, divide by what is on the bottom.

2.5m× 1.09 yrd1m

=(2.5 )× (1.09 )÷1=2.72 yrds

Step 6: Make sure your answer has the correct units. Yup, we’re good.Here’s one way you can look at conversions:

We are going to try this together. I suggest folding the page down the middle. You try following the steps on the left, and afterward check the solutions on the right.Practice Problem: Guided Single Step ConversionConvert 325 millimeters to meters. Remember that 1 m=1000mm.Steps SolutionsStep 1: Write down the known values and the unknown values.

Step 1: Write down the known values and the unknown values.Known: 325 mmUnknown: ? m

Step 2: Find the conversion factor that gives a ratio between meters and yards.

Step 2: Find the conversion factor that gives a ratio between meters and yards. 1 m=1000mm

Step 3: Write down what you were givenStep 4: Multiply by the conversion factor. Make sure that the units are kitty-corner from one another.

Step 3: Write down what you were givenStep 4: Multiply by the conversion factor. Make sure that the units are kitty-corner from one another.

325mm× 1m1000mm

Step 5: Multiple what is on top, divide by what is on the bottom.

Step 5: Multiple what is on top, divide by what is on the bottom.

325mm× 1m1000mm

=(325 )÷ (1000 )=0.325m

Step 6: Make sure your answer has the correct units.

Step 6: Make sure your answer has the correct units.0.325 m

Occasionally, you will have conversions that involve more than one step. In that case, you will need to use more than one conversion factor. The key to this is always making sure the units you want to cancel are kitty-corner to one another.Example Problem: Multi-step ConversionsConvert 13 yrds to centimeters. Remember that 1 yrd= 3 ft 12 inches=1 ft

1 inch=2.5 cm

Answer

A Note About TimeOccasionally, you won’t be given the conversion factors you need. In this class, this will almost always be in conversions involving time. Why? Because you already know the conversions- you learned them in second grade. Just relax and remember that you already know that 1 yr=365 days, 1 day=24 hours, 1 hr=60 min, 1 min=60 seconds.Example Problem: Converting TimeIn two years you will be in college. How many minutes do you have left to be a high school student (assuming you are still a high school student the summer after you graduate)

Answer1051200 minutes left

Level 4: Problem Solving ExpectationsOne thing everyone loves about physics: there is loads of partial credit in this class. Let’s say you are solving a problem, and you have literally no idea what is going on. It happens. You start to sweat, you look at your equations sheet (which you are allowed on tests and quizzes) and pick one of the three equations you know we’ve been using a bunch. You write it down and leave the rest blank. When I’m grading your test, I use a very specific grading rubric. If I look at the problem and know know that you had no idea, but see that you randomly guessed the right equation, I still have to give you that point. If you learn the steps below, you will be able to bluff tons of points out of your test. It’s not cheating. That’s just how we roll in physics.I’m going to show you these steps by using an example problem. To keep things easier and less physics-y (for now), I’m going to make up some fake equations for you to use.

Fake Equation

Friendship=(Laughs ) ( Inside Jokes)(Kindness)

(Rumours)2

or, if we made that shorter:

F= LIKR2

In this class, you will often be given equations like this. They won’t always teach you about friendship, but sometimes they will tell you the secrets of the universe. No joke. Now we are going to use this equations to solve a problem. Right now, take out a separate sheet of paper. Keep this paper, as you will need to show it to me in order to take your challenge. In the problem below, I am going to tell you steps on how to solve the problem. You are going to first try to do the step on your paper. You are then going to check the right side of the paper to see if you did it correctly.Example Problem: Problem Solving ExpectationsKayla and Maddi are friends. This week, they had 12 laughs together, made up 2 inside jokes and committed three acts of kindness. Unfortunately, Kayla did start those two rumors about Maddi and Tom. How good is their friendship right now? The units for friendship are “Hugs”.

Friendship=(Laughs ) ( Inside Jokes)(Kindness)

(Rumours)2F=

LIKR2

You try it. Done CorrectlyStep 1: Write down everything you know.

Step 1: Write down everything you know.L=12 I=2K=3R=1

Step 2: Put a question mark beside what you don’t know.

Step 2: Put a question mark beside what you don’t know.L=12 I=2K=3R=1F=?

Step 3: Write the equation. In almost every problem all year, this will get you a point.

Step 3: Write the equation.F= LIK

R2

Step 4: Put the numbers into the equation. Do not erase parts of the equation you just wrote down. You need to keep that intact. You will write this below.

Step 4: Put the numbers into the equation.

What you wrote before F= LIKR

Now add F=

(12)(2)(3)(2)2

Step 5: Solve the math. You can take as many steps as you want for this. If you are good at math, feel free to “plug n’ chug” at this point- plug it into your calculator and have it tell you the answer. If you struggle in math, take your time. I don’t care if you need to write a million lines as long as you get the right answer.

Step 5: Solve the math.

F=(12)(2)(3)

(2)2

F=18

Step 6: If you like it then you shoulda put some units on it.

Step 6: If you like it then you shoulda put some units on it.

F=18Hugs

Step 7: Box it up, cause it’s physics Christmas!Boxes let me know where you answer is.

Step 7: Box it up, cause it’s physics Christmas!

F=18Hugs

Let’s have you try one on your own now. This time, I’m going to put out three fake equations. You are going to have to pick which one makes the most sense to use.

Attraction=(Looks)(Humour )(Kindness)(Meanness )2(Arrogance)

=A= LHKM 2 A

Education= (Perseverance )2( Intelligence)(Laziness)(Doubt )

=E=P2 ILD

Social Life=(Friends)(Money)(Transportation)Awkwardness

+FreeTime=S=FMTA

+T

Practice Problem: More Problem Solving ExpectationsIn a typical work, Sam spends 12 hours on his education. He perseveres through hard tasks four times. He is lazy only three times, and doubts himself once. How intelligent is Sam? Intelligence is measured in brains.Before you move on try this in your notebook. Don’t read the solution before you try. Keep the sheet- I may ask to see it.SolutionIf you did this problem right, your work should look something like this:E=12P=4L=3D=1

I=?

E=P2 ILD

12=(4)2 I(3)1

12=16 I3

(12 ) (3 )=16 I

36=16 I

3616

=I

2.25=I

2.25Brains=I