 Hey everybody welcome to tutor terrific if you've reached this video you've reached the first in a series of physics videos that could work as a sort of honors level or rigorous high school physics course or an entry-level college physics course and we're gonna go through an overview of all of physics in This series and it's gonna be a quite long series because it's a whole course I'm gonna break it up into chapters and it's not based on calculus. So this is a non-calculus based physics course if you will so The first thing I want to discuss with you is what physics is because that's a big question a lot of people who are beginners to This science ask what is physics? So we need to go over that there is physics in every part of your life Everything you interact with physics is going on all around you. So consider this guy strumming a guitar So there's lots of physics in this picture We've got the strings when he plucks the strings they vibrate and damping occurs Which lowers the amplitude the sound of the vibration which vibrates out in all directions We've got a sounding board and we've got a sounding chamber that amplifies the sound the fact that he's able to hold the Guitar up and it's not falling and he's not falling through the floor is another example of Forces in physics that we're gonna study in this course So there's lots of physics going on in this picture as well in this scene We've got a balance of forces here the tension in the string balancing gravity and balancing friction creating a nice smooth Trajectory for this guy. See uses the wind to kite surf his way to a wonderful day We've got some viscosity which is fluid type of friction between the board and the water. We've Got buoyancy which allows him to stay afloat above the water and we've got air resistance Which is the whole reason he can even kite surf at all and in this picture at the Volcano the eruption you could see that the lava pieces are flowing in parabolic paths upside down parabolas We've got the fact that some of this lava seems to be flowing downhill With the help of gravity and it seems to take certain paths down the hill which Are interesting. It's definitely a physics phenomenon as to why they take certain paths and not others The fact that a different type of particle the smoke is actually buoyant in the air and floats in the air at a certain altitude We've got the radiation the black body radiation from this super hot molten lava and the hotter it is the The brighter it is and the closer to the blue end of the spectrum The the light frequency is so there's plenty of physics in that picture as well And of course the classic model of the Sun and Earth here We could see that the Sun is very radiant It's actually a plaza which is a force state of matter in which the electrons and the nucleus are completely disassociated Lots of photon radiation here We've got the fact that the Sun and the Earth are connected by gravity We've got this shadow behind the earth here And the earth itself is a wonderful phenomenon in physics the fact that we're even alive on this earth And we're a certain distance from the Sun and everything's pretty stable We've got all the other stars which of the Sun is one type It's just the type that we are gravitationally attracted to and in an orbit around and These other stars are just like the Sun. They're just a lot farther away They're so far away that we're seeing them in the past because it takes light several tens to hundreds to thousands of light years to reach us and so this is a plenty of physics going on here mostly bound by gravity and Of course, there's nuclear fusion going on in the Sun as well, which fuses hydrogen atoms into a helium nucleus So back to the main question of what physics is I want to make that very clear to you There's two definitions of physics one. That's less formal and one. That's a lot more formal So here's an informal Definition of physics the study of matter Energy and how they are related very simply put that's a good definition of physics the study of matter Which you learned about in chemistry if you've already taken chemistry energy Which are going to learn a lot more about in physics and the relationship between those two Content ideas they're very large categories of things to study and so we're going to study both Mainly we're going to study the relationships between both Forces of course Play a huge role in that relationship. All right now the more formal definition of physics is this the study of the Set of principles that govern the properties and interactions between matter and energy at all Scales in our universe, so it's a set of principles Okay, set of laws or theories and I'm going to go through those types of truth terms in a later slide on this lecture But we're going to look at a set of all these principles that govern interactions and properties between matter and energy at all scales down to the Subatomic scale all the way up to the scale the size of the universe there are principles that govern how things interact with each other and The properties that they have that's another more formal definition of physics All right now if there's one thing you learn in science That you do not forget it would be the scientific method the scientific method There are lots of versions of the scientific method. My method has six steps Okay, step one when you are engaging in this method is to determine a question that needs to be answered And then ask that question if you just hypothesize Maybe that'd be interesting to study, but you don't actually ask yourself the question such that you want to answer the question You're not really engaging in the scientific method. So that's step one to really ask that question now First before you do go straight to the experiment. No, there's many steps before that first You want to conduct Background research you want to see if anybody else has already answered that question and if no one has or No different groups of people have their own answers to the question You want to research how other people have investigated the problem or similar problems to get some extra Information before you go to the next step based on your research and your question You're going to establish a hypothesis, which is a proposed answer Your hypothesis will try and answer your question based on your research Then once you get to the hypothesis you will devise and conduct step four an experiment to test Your hypothesis you want to see if your hypothesis is true You're not assuming it's true to assume your hypothesis is true without testing is bad science So you definitely need to set up an experiment You don't just do the experiment and say oh I figured it out You have to analyze the data from the experiment in physics your experiment should produce data that you can analyze It's the data that matters So you need to set up a system that can analyze that data and figure out how it pertains to your question Once you've analyzed the data, you'll be ready to draw last step step six a conclusion Now your conclusion would best be served by being communicated through you So you want to communicate your conclusion in a way that others can understand in a research report a lab report or formal paper in a scientific journal or Presentation it like a TED talk you want to communicate your conclusions to the scientific community and the world That in itself those six steps are the scientific method. So as some of you may know I like to drag race. I like to build cars for racing and Back in 2015 I conducted an experiment with my car. I had taken it to the track and I had Run a time just after I built the car. I built the head I'd worked on the suspension the transmission. I tuned the car and I wanted to do really well at the track so my first time of the track sets the build is in this video and We're gonna check out how I did my first drag race day since the car was built Racing for those of you don't know it's a quarter mile single shot Reaction time of the green light matters in your laps time and speed at the other end matters. So It's hard to see but I actually got a 15.413 second elapsed time with the 88 mile an hour trap speed That's how fast you're going at the other end So I of course wanted to do a lot better than that after all the money I'd spent But that was my baseline result from that first day of drag racing So immediately as a racer I asked the following question. How can I go faster? Okay, and I really wanted to go faster after all that money I built maybe as few tweaks or one tweak in particular would make a difference and so if you notice on that car I've got some interesting front wheels. I've got some drag radials on there. The wheels are quite heavy But the drag rails are quite sticky. However, the wheels weren't very They weren't perfectly round So we're gonna study angular momentum and learn how that can be a problem for you What I did is I went to a very famous Website for people who have this car. It's CB7 tuner.com It's a forum where people could go to learn about their car swatch and See how other people document their modifications of the car and ask questions and interact with this community of people who love this Car and so I learned quite a bit about what I could do and so I established a hypothesis a really simple Idea is to put the stock sport wheels that I bought as a set of four back on the front with the sport tires and Which are a lot lighter than the drag radials over here With those giant wheels and I was gonna see if I could reduce my time 0.413 seconds that would take all that time in the 15 second Laps time away and bring me down to the put where I could break into the 14 second range That was my goal and then it was time to conduct the experiment to test this so in August of 2015 I went back to the track and I Did another run so let's check out what I did Remember I didn't change anything but the front wheels 1528 89 miles an hour So Let's analyze this data It appears as though I reduced my laps time But by less than point two seconds not the desired point one four point four one three seconds that I wanted or more And so while I did reduce my time. I didn't reduce it by the amount. I want it so my conclusion is this while Putting on the stock tires and rims on the front wheels does reduce the elapsed time by a significant amount It did not reduce the elapsed time by the desired point four one three seconds or more So more research and work has to be done to determine What can be done to reduce the elapsed time by the desired amount that is a formal conclusion This guy's is an example of using the scientific method So let's discuss now the truth terms in physics We use quite a bit of these and if you take a geometry which you should have before you try physics You learn quite a few others like conjecture and theory and things like that Model is a very important truth term It's an analogy or mental image of a phenomenon in terms of something more familiar So it's trying to if I use the verb form model a phenomenon in real life a Theory something also used in physics and all sciences is a more broad and detailed Statement that gives Tatively testable predictions you can test a theory because it has measurements involved or it can be tested using measurements a Law is a concise, but general statement About how nature behaves and it's stated as a relationship or an equation So it's more general than a theory and Then lastly a principle which is even more general than a law and it cannot be found valid by scientific experiment It's a it's more of a way to conduct yourself or a way to think about something We're gonna look at a few of those principles throughout this physics course alright guys Thank you so much for watching this video check back for more of these physics videos There's gonna be a lot of them coming out soon. This is Falconator signing out