Here are the important screenshots from last week:

PhyFl18-2.5.1 Chuck with my childhood dream girl

PhyFl18-2.5.1A Here is a good example of how to do board work using Deipa

PhyFl18-2.5.1B Another good example

PhyFl18-2.5.2 MONDAY

PhyFl18-2.5.3 2.12.1

PhyFl18-2.5.4 2.12.4

PhyFl18-2.5.5 I the speed of light is about a million times faster than the speed of sound. That is why you see the lightning and then hear the thunder 5 seconds later if the lightning was a mile away. (since speed of sound is about 1100 ft/sec which is about a mile every 5 seconds. Still, that’s pretty daggone fast. I wish I could go a mile in 5 seconds. That would give me a lot more time at home at lunch. Just sayin.

PhyFl18-2.5.6 TUESDAY

PhyFl18-2.5.7 3rd Orange Equation derived part 1

PhyFl18-2.5.7B 3rd Orange equation derived — part 2.

PhyFl18-2.5.8 So let’s talk guns and bullets.

PhyFl18-2.5.9 What is the acceleration of the bullet in the barrel of a gun?

PhyFl18-2.5.10 2.12.5b How long does the bullet stay in the barrel?

PhyFl18-2.5.11 WEDNESDAY

PhyFl18-2.5.12 2.12.10a the physics part is not bad

PhyFl18-2.5.13 weird units, but we can’t have double decker fractions in our unit analysis.

PhyFl18-2.5.14 2.12.10a. Easiest way to work this difficult problem.

PhyFl18-2.5.15 2.12.10b

PhyFl18-2.5.16 THURSDAY

PhyFl18-2.5.17 Back of the Envelope Demo of a ball rolling up and down the ramp. How to determine the hidden acceleration

PhyFl18-2.5.18 2nd hour’s BOE

PhyFl18-2.5.19 3rd Hours BOE

PhyFl18-2.5.20 6th hours BOE

PhyFl18-2.5.21 7th hours BOE

PhyFl18-2.5.22 Ball up and down ramp in general

PhyFl18-2.5.23 Perfect bow tie. Positive right triangle represents the ball rolling up the ramp, brown right (negative) right triangle represents the ball rolling down the ramp.

PhyFl18-2.5.24 FRIDAY

PhyFl18-2.5.25 handgun bullets vs. rifle bullets.

PhyFl18-2.5.26 bullet stuff

PhyFl18-2.5.27 bullet stuff

PhyFl18-2.5.28 bullet stuff

PhyFl18-2.5.29Rifling the inside barrel of a gun made the bullet come out spinning which made it much more accurate. Sort of like a spiralling football throws much more accurtately than a knuckle ball football.

PhyFl18-2.5.30 Average acceleration of the bullet in the barrel. THis is a gross approximation. We spent most of the hour talking about why it was wrong. We HAD to assume it was flat or we couldn’t have attackjed the problem with the Orange Trio Equations

PhyFl18-2.5.31 The acceleration is zero when the contained explosion first occures and the horizontal acceleration of the bullet is zero when the bullet leaves the barrel since there is no more pressurized expanding gas pushing it through the chamber. so the parabolic shape is better than a flat a vs. t, but it is still wrong. The reason involves p waves.

PhyFl18-2.5.32 Even though the average acceleration vs. time is a gross approximation of the true instantaneous acceleration, we can still use the approximation to accurately determine the final velocity AND the length of the barrel. Wow, this Physics stuff is pretty cool. Knowing a little bit about the acceleration of a bullet in a barrel tells me how long the barrel is. Magic? Nope, physics with a little calculus.

PhyFl18-2.5.33Kinetic theory needs to be brought up to start to understand why the a vs. t graph is not parabolic in shape. Basically, Kinetic THeory says that everything is made os molecules (this idea is only a little over 100 years old). Phillip Leonard was a jerk and turned out to be a Nazi, but he WAS right about molecules. Einstein believed him, but he hated Einstein because he was a Jew. Can you believe that? That is like thinking someone is less than you because of the color of their skin. What kind of a monster would ever believe that? Anyway . . . the air molecules in this room are moving about 800-900 mph. You like that because it makes your skin vibrate at just the right frequency. Ahhhh. . . warmth.

PhyFl18-2.5.34 So molecules (and therefore everything) has three possible types of motion.

PhyFl18-2.5.35 There are different types of waves. We are talking about pulse waves today, but there are Shear waves, Raleigh Waves, Love waves. Most waves we deal with in Physics (like sound waves) are P waves. The P stands for Pulse or Pressure)

PhyFl18-2.5.36 . . . .

PhyFl18-2.5.37 Sounds that reach your ear originated with a manipulation of the air molecules by the p waves eminating from the source. It still blows me away how air molecules are so quickly rearranged into areas of compression and areas of rarefaction. We can measure this with an oscilloscope.

PhyFl18-2.5.38 SOme classes have n’t gotten to this yet, but this is the upshot of the p wave inside the barrel of the rifle. It makes the graph of a vs.t front loaded.

PhyFl18SS2.3.4 future millionaires and billionairs.

PhyFl18SS2.3.5 AP Physics students take advantage of a few free minutes to prep for one of those killer tests.

PhyFl18SS2.3.6 Foosball Championship

PhyFl18SS2.3.7 . . .

PhyFl18SS2.3.8 . . . n as I get time

PhyFl18SS2.3.9 Brackets

PhyFl18SS2.3.10Winners . . .Cantina Bucks!!

PhyFl18SS2.3.11 1st hour’s class data from Galileo’s Experiment

PhyFl18SS2.3.12 2nd hour’s class data from Galileo’s Experiment

PhyFl18SS2.3.13 3rd hour’s class data from Galileo’s Experiment

PhyFl18SS2.3.14 6th hour’s class data from Galileo’s Experiment

PhyFl18SS2.3.15 7th hour’s class data from Galileo’s Experiment

PhyFl18SS2.3.16All the possible linear graphs of motion that you will experience today.

PhyFl18SS2.3.17 An inverse relationship

PhyFl18SS2.3.18I show this to give you an example of all the ways to write the letter k. So you have to be careful withs your caps and lower case and cursive.

PhyFl18SS2.3.19 Your guess for what the graph of a ball rolling up the incline and back down looks like.

PhyFl18SS2.3.20 . . . .

PhyFl18SS2.3.21 . . .

PhyFl18SS2.3.22 . . .

PhyFl18SS2.3.23What the graph SHOULD look like. The furthest it goes is called the apex.

PhyFl18SS2.3.24 Apogee Perigee

PhyFl18SS2.3.25 Simple Harmonic Motion (SHM).

PhyFl18SS2.3.26 Damping

PhyFl18SS2.3.27 The slope of the secant is the average velocity. The slope of the tangent is what we REALLY want. because it is the instantaneous velocity.

PhyFl18SS2.3.28 Drawing a tangent line is easy for circles. It is simply perpendicular to the radius. The problem Newton and us has is that we aren’t finding the tangent to a circle. We are finding the tangent to a curve.

PhyFl18SS2.3.29 We use this cool trick to “fool” the algebra (secant slope) into becoming calculus (tangent slope) at that one brief shining moment that is the midtime of a time segment for a parabola. (This only works in parabolic situations.)

PhyFl18SS2.3.31 We get two very good equations out of this

PhyFl18SS2.3.32 HEre are the three equations we are goin gto use to determine the 3 Orange kinematic Equations next week. Then we can stop all this graphing.

PhyFl18SS2.3.33A very valuable equation

PhyFl18SS2.3.34 Going to the graph below in a trio is accomplished by taking the slope of the graph above.

PhyFl18SS2.3.35 m/s/s is the same thing as m/s^2

PhyFl18SS2.3.36 Slope (or derivative) to get to the graph below. Area or integral to get to the graph above.

PhyFl18SS2.3.37From sheet 2.8

PhyFl18SS2.3.38 We rolled the ball down the 9 meter tube out in the courtyard. We looked down the holes which we drilled every 1 meter.

PhyFl18SS2.3.39 1st hour data from the ball rolling down the tube

PhyFl18SS2.3.40 2nd hour data from the ball rolling down the tube

PhyFl18SS2.3.41 3rd hour data from the ball rolling down the tube

PhyFl18SS2.3.42 6tht hour data from the ball rolling down the tube

PhyFl18SS2.3.43 7th hour data from the ball rolling down the tube

PhyFl18SS2.3.44 Remember, nature paints with a broad brush. Relationships are relatively simple in the macroscopic world. The middle curve above is too complicated for macroscopic relationships that we study in kinematics. Look for the general trends. Don’t go chasing after anomalies.

PhyFl18SS2.3.45 We started to look at the Beautiful Patterns

Here are the more important screenshots from last week:

PhyFl18–SS2.2.1 Go ahead and back fill all the boxes behind the Boltzmanns (and Rockets).

PhyFl18–SS2.2.2 If you grade goes down after the A and B tests, you can get back in the game with GBB. Also, always keep up your Notebook, Packets, and stamps. If you do, you’ll end up with an A of B in class.

PhyFl18–SS2.2.3 problem 2.6.2

PhyFl18–SS2.2.4 Problem 2.6.5

PhyFl18–SS2.2.5 1st hour data

PhyFl18–SS2.2.6 2nd hour data

PhyFl18–SS2.2.7 3rd hour data

PhyFl18–SS2.2.8 6th hour data

PhyFl18–SS2.2.9 7th hour data

PhyFl18–SS2.2.10 A nice simple drawing capturing the essence of acceleration. Now we just have to graph it.

PhyFl18–SS2.2.11 The world’s first true physics equation. It’s about as far as Galileo got before receiving the glass from the Danes. The crazy thing was that he figured out the relationship between position and time for an object undergoing acceleration due to gravity and he did it all WITHOUT the benefit of graph paper because Rene Descartes hadn’t hadn’t been invented yet.

PhyFl18–SS2.2.12A One way to figure out which class got closest to the truth (in other words, who was the most accurate) is to look at what the acceleration should have been theoretically and then see what each classes acceleration really was. THis FBD of the forces acting on the ball will lead us to the correct theoretical value for acceleration. We will do lots of these FBD later in the year. They come in pretty handy.

PhyFl18–SS2.2.12B FBD’s are the most important thing you will learn in this class. DOn’t worry , this is just a preview. I’ll work this one this week to determine what the acceleration should be for the ball vs. what each class found it to be and we will see who gets the stamp.

PhyFl18–SS2.2.13 Love this quote.

PhyFl18–SS2.2.14 about right

PhyFl18–SS2.2.15 Look at the detail of the original (or one of the original) telescopes made by Galileo and Salviati (his assistant.)

PhyFl18–SS2.2.16 Some of the optics that wouldn’t be figured out until Newton did his early work with prisms.

PhyFl18–SS2.2.17 We discussed where all the energy in our solar system comes from in the core of the sun. This over simplified view of the fusion of protons is wrong . . .

PhyFl18–SS2.2.18 This is the correct flow chart.

PhyFl18–SS2.2.19 some of the byproducts of the nuclear fusion reaction in the core of the sun.

PhyFl18–SS2.2.20 The greatest irony of our solar system. Deadly gamma rays produced in the core of the sun is the source of all life on earth.

PhyFl18–SS2.2.21 It takes the gamma rays (wavelength around 10pm) anywhere from 50,000 years to 10 million years to get from the core of the sun to the surface of the sun (then only 8.2 minutes to get to earth). The deadly gamma wave is destructively interfered with by other wavelets of energy while it is on its outer journey inside the sun. When waves are destructively interfered with they lose some of their energy (which shows up as lower frequency). By the time the wave packet of energy that was originally 10pm in wavelength gets to the surface of the sun and is ready for the 8.2 minute journey to the earth its wavelengths are scattered somewhere between from 10nm (UV) to 1mm (far IR). So that original deadly gamma ray gives us our heat, our visible light and the still dangerous UV light.

PhyFl18–SS2.2.24 the journey of the deadly gamma ray

PhyFl18–SS2.2.26 It looks like at least three groups of physics students have taken on the task of hanging mars and venus somewhere in Norman.

Here is what happened this week: I will add captions as I get time this week:

PhyFl18SS2.1 A Red Duet. The graph below is the slope (derivative) graph of the graph above. When you have a negative slope, you turn it into an upside down right triangle. When you have a positive slope you turn that into a right side up right triangle. Pick a color for all the negative slopes (velocities) and another color for all the positive slopes (velocities).

PhyFl18SS2.2 Here’s another Red Duet. Here we started with the velocity vs. time graph on bottom and from there we found the position vs. time by finding the areas (called integration) of the segments of the graph below.

PhyFl18SS2.3 we are doing the same thing here, but here the equations for integration are introduced.

PhyFl18SS2.4 Here is the symbols for integration and what each part of it means.

PhyFl18SS2.5 Here’s another example of integrals. Basically, taking the integral of a function is telling you how much area is accumulating as you go from left to right.

PhyFl18SS2.6 Good use of color.

PhyFl18SS2.7 Finger dance

PhyFl18SS2.9 Will add caption later

PhyFl18SS2.8 what showmen!

PhyFl18SS2.8b Finger Dancing with pearls.

PhyFl18SS2.10 Socrates –> Plato –> Aristotle –> Alexander the Great. Greatest Teacher student combo in history.

PhyFl18SS2.11 5 old dudes and a young grad student.

PhyFl18SS2.12 Will add caption later

PhyFl18SS2.13 good notes

PhyFl18SS2.14 A rabbit is made up of only four elements. See how easy it was back then. Chemistry must have been an “easy A” back then.

PhyFl18SS2.15 A famous painting of Copernicus. Notice his Heliocentric view of the universe is shown behind him.

PhyFl18SS2.16 Geocentric view of the universe. Thanks Aristotle for setting us back 2000 years.

PhyFl18SS2.17 Copernicus in the game “Assassin’s Creed”.

PhyFl18SS2.18 Leo’s main goal in life was to fly. Here he thinks about how he would accelerate towards the ground if he jumped off the Leaning Tower of Pisa. He was the first to try to quantify the acceleration due to the Earth’s pull. He was wrong, but at least he started thinking about it.

PhyFl18SS2.19 My favorite self drawing of Da Vinci.

PhyFl18SS2.20 Galileo’s proposed wings

PhyFl18SS2.21 Galileo’s wings. Not a big tat guy, but this one is awesome.

PhyFl18SS2.22 We had about 50 students in the room to see Dr. Nash.

PhyFl18SS2.23 Dr. Nash presenting. He’s got a big week this week with his big proof of concept.

PhyFl18SS2.24 Giovanni Bruno burning at the stake in 1600.

PhyFl18SS2.25 1604 was the beginning of Physics.

PhyFl18SS2.26 A young Galileo

PhyFl18SS2.27 Galileo’s finger on display at the Galileo Museum in Florence. There is a really interesting story to this.

PhyFl18SS2.28 Galileo recanting his beliefs in front of the Inquisition. It was either recant of burn at the stake like Bruno in 1600.

PhyFl18SS2.29 A very good recreation of Galileo’s ramp he used trying to determine acceleration due to the Earth’s pull. He added the bells in later trials.

PhyFl18SS2.30 Galileo’s bells

PhyFl18SS2.31 . . .

PhyFl18SS2.32 We will be rolling on Monday as well.

PhyFl18SS2.33 Friday night in the Physics building

PhyFl18SS2.34 A new classic photo with Einstein in the Physics building

Here are the most important screenshots from this week:

PhyFl18SS1.7.1 sheet 1.7.5 ant crawling around basketball.

PhyFl18SS1.7.2 sheet 1.7.6 A little circular motion GSUA

PhyFl18SS1.7.3 Sheet 1.7.7 You can think about any type of linear motion on the surface of the earth as if it were circular motion since the world is a big ball. just like the ant crawling around the basketball.

PhyFl18SS1.7.4 sheet 1.9.(the top of the back) From our pinwheels in the courtyard.

PhyFl18SS1.7.5 Sheet 1.9.5 The birth of the cosine function. That’s all sines and cosines are. They are circular motion spread out over time. Actually, they are one dimension of that circular motion spread out over time. In this case here, the vertical component of the circular motion is laid out over time. See the animation on my website. If you can get this one thing down it will make physics and math so much easier for you.

PhyFl18SS1.7.6 1st hour trippin run.

PhyFl18SS1.7.7 1st hour x vs. t piecewise function from the trippen run showing the 5 different interval velocities and the overall average velocity

PhyFl18SS1.7.8 2nd hour trippin run

PhyFl18SS1.7.9 2nd hour x vs. t piecewise function from the trippen run showing the 5 different interval velocities and the overall average velocity.

PhyFl18SS1.7.10 3rd hour trippin run

PhyFl18SS1.7.11 3rd hour x vs. t piecewise function from the trippen run showing the 5 different interval velocities and the overall average velocity

PhyFl18SS1.7.12 6th hour trippin run

PhyFl18SS1.7.13 6th hour x vs. t piecewise function from the trippen run showing the 5 different interval velocities and the overall average velocity

PhyFl18SS1.7.14 7th hour trippin run

PhyFl18SS1.7.15 7th hour x vs. t piecewise function from the trippen run showing the 5 different interval velocities and the overall average velocity

PhyFl18SS1.7.16 the old baseball example of distance vs. displacement. For example: If I hit a double, my distance would be 180 ft, but my displacement would be 127 ft.

PhyFl18SS1.7.17 An example of a weighted average a teacher might do for grades.

PhyFl18SS1.7.18 This is a new type of graph for us. It is called a slope graph. It is also called a derivative graph. In this case it is a velocity vs. time graph. It shows what the five interval velocities of the trippin run. This is a VERY important screenshot. It is where we are going next and it is the beginning of your journey into graphical calculus. This graph is the derivative part of the x vs. t graph. Together they form red duets. An example of a weighted average for our step function can be seen by comparing the darker flat segment compared to the 5 orange segments. The darker segment is the weighted average of the 5 orange segments.

I will continue to add captions. All should be added by 10:00PM, 9/23/18.

PhyFl18SS1.6.1 The resultant vector needs to be in a different color. A proper description of a vector requires magnitude, units,angle, quadrant.

PhyFl18SS1.6.2 All angles are measured from the horizontal (with some exceptions) If it is a map view, this is how you describe the quadrant that you are in.

PhyFl18SS1.6.3 A displacement vector (or any vector for that matter always starts at the begining and is a straight arrow to the end. The path that the object takes does not matter. ∆s in blue is a displacement vector. It only cares about the beginning position and the final position. The displacement vector of my life would start in Ponca City Hospital and probably end where I am teaching at NHS. It doesn’t care where I have visited and lived in my life. It only cares about where I was born and where I died. It would be a 124 milelong straight displacement vector.

PhyFl18SS1.6.4 A vector at an angle is the hypotenuse of a right triangle. So if you are going at 4 yds/sec at 45° N of E, you represent that with an arrow that has a length of 4 yds/sec (at whatever scale you assigned that velocity vector), but you are also going 2.8yds/sec east and 2.8 yards per second north. You are actually going all three velocities at once. Weird, huh? Either we do it this way with 2D motion or you learn how to plot everything in 3D (∆x,∆y, and ∆t).

PhyFl18SS1.6.5 We went out to the courtyard and did a couple of pinwheels. From this exercise, you should start to get a feel of circular world vs. linear world. We all went the same omega (angular velocity), but we went different 2D linear velocities.

PhyFl18SS1.6.6 Still on the courtyard pinwheels. If we say it took us 10 seconds, then we had an angular velocity of 2π/4 radians per 10 seconds (=π/20 radians per second)

PhyFl18SS1.6.7 So far we have talked about displacement and velocity being vectors (magnitude and direction) and time is a scalar (no direction). What about baby omega? Is it a vector or a scalar?

PhyFl18SS1.6.8 It turns out that omega (angular velocity) IS a vector. But what about it’s direction. Since the object is rotating (or at least going in circles) how do you represent this circular motion with a straight arrow? You gotta go third dimension bro. So you represent the omega with an arrow coming out of the page for counter clockwise rotation (CCW). You represent an arrow coming out of the page with a dot and a circle around it (sometimes just a dot)

PhyFl18SS1.6.9 You represent clockwise rotation (CW) with an arrow going INTO the page. An arrow into the page looks like the arrows tail feathers left an impression on the page (like an “x”). The arrow is along the axis of rotation.

PhyFl18SS1.6.10 Circular world vs. linear world. For wevery relationship (think equation) in linear world, there is a corresponding equation in circular world.

PhyFl18SS1.6.11 Definition of a radian. The question came up . . . “Why don’t radians have any units?” Because they are a ratio of the arc length of a circle (∆s) and the radius of that d

PhyFl18SS1.6.12 From the three base equations (on the left) we derived a very useful, very important equation in Physics which bridges linear world to circular world. You will have to know this derivation for TEST 1B. .

PhyFl18SS1.6.13 Here’s the good old what is the omega of the second, minute, and hour hand which you will find in every Physics textbook.

PhyFl18SS1.6.14 converting radians per second to rpm (revolutions per minute) Like what your tachometer measures on the dashboard of your car.

PhyFl18SS1.6.15 From that bridge equation we derived, here is another useful minibridge equation relating linear velocity to angular velocity.

PhyFl18SS1.6.16 I spun the wheelchair tire in front of the classroom and you timed it. We got 5.7 radians/sec. when multiplied by the radius of the tire we see that the outside of the tire is rotating at 1.6m/s

PhyFl18SS1.6.17 The period (Tp) is the time it takes an object to complete one revolution. Like the period of the earth is 24 hours or the period of the earth around the sun is 365 days. Period can also mean the time it takes a pendulum to come back to its original position. Period is the inverse of frequency.

PhyFl18SS1.6.18 Here we were looking at the period of the spinning wheel in front of the class.

PhyFl18SS1.6.19 Period talk.

PhyFl18SS1.6.20 The wheel spinning up front. Using the brige equation to determine its velocity.

PhyFl18SS1.6.21 Here we are trying to figure out how many miles per hour the spinning wheel would be going it it were attached to a bicycle.

PhyFl18SS1.6.22 The point I was trying to make with this discussion was that the moon is moving at 2300mph, but appears to us to be moving hardly at all. The reason for this is the very long radius. Since omega = v/r. Since r is soooo big, it wipes out the huge v. the omega is what we perceive as we stand below an object rotating above our head. A jet may be going at 600mph, but because its radius (from us) is, say, 50,000 ft, it doesn’t have a very big omega so it doesn’t seem like it is going that fast to us. There are probably those out there who would call its speed of 600mph “fake news” because they themselves do not understand circular motion kinematics.

PhyFl18SS1.6.23 so when the radius is large compared to the velocity, the object appears to be going slow to us down below. This sounds like a good essay question for Test 1B.

PhyFl18SS1.6.24 THT1A.18

PhyFl18SS1.6.25 THT1A.18

PhyFl18SS1.6.26 If you see “SH” on your test from ym grading it means you should have used a ruler. It stands for “shaky hands”

PhyFl18SS1.6.27 If you see this on your test from my grading it means that I followed your mistake so you missed less than you would have if I was a computer and was grading your test.

PhyFl18SS1.6.28 It is much better the search the Facebook group for what your are looking for than the scroll scroll scroll.