Video Gallery

Energy Ch#5 Paul Hewitt

Go to Video Gallery Added Oct 26, 2021 •

Copy this URL:
Embed code:	<iframe class="edlio-embed-player" type="text/html" width="640" height="360" src="//www.valenciavikings.com/apps/embed/?v=328705" frameborder="0" allowfullscreen></iframe> Change dimensions

Go HD

An overview of energy including: Potential Energy Kinetic Energy Friction Energy Electrical Energy Heat Energy Light Energy Conservation of Energy is emphasized in the video. Energy is like money. It goes from one form to another. You can transfer money to your checking account from your savings account. You can store it in a gift card, or a Venmo account. You can even "store" money in "stuff" to sell later.

Show Transcript

what's happening Young Thug Hackensack what is it begins with 8 energy how many people feel energy how many people wish they had more would be talking about such thing now we talked before about the idea of momentum remember momentum and inertia and motion and how do you get something moving if it's not moving how do you change the momentum of something you push and you provide what's called an Impulse impulse right impulse is not only for it's not how hard you put only that will tell you how much momentum change you'll get it's how long you push and we talked about how long in terms of time reset force x time would be numerically equal to you multiply the force that you was earning something huh X not the momentum but the change in momentum that you you produce by pushing it and so we talked about this you know and we call this idea here how hard you push X the duration in which bushing takes play we had a name for that see if your neighbor remembers the name don't be a nymph now come on to be a little brother right cancel Wayside impulse is a change in the quantity of inertia and motion moving inertia we call that what that one for the we call it begin with an m momentum okay don't be shy and that's what we talked about right and we said big changes in momentum you'll have what kind of impulses for small changes in momentum you'll have what kind of impulse begin with S larger or the same as if bouncing does not occur larger and we can show that with this device here here's a dart it's like a dark and I have a sharp nail in there and what I'm going to do is I'm going to lift the jar. And I'm going to allow it to swing against that wall going to make a collision watch this the block did not tip I'll try it again the block did not tip this time I'm going to remove the point and now I have just rubber here this time when I swing it it's going to bounce and when it bounces more impact or less wow hands down no contest I don't even have to lift it even has high and even looked at this I watch a so bouncing more change in momentum when it bounces a certain change it stopped again more change or less more change more change in momentum means what kind of impulse radar impulse and you saw that and it's the impulse to knock the block over we're not going to talk about impulse and momentum today we're going to talk about a renovated idea how hard you push to get something going as one thing but how long you push is also important so far we talk about how long in terms of time how long in terms of what you watch me we can talk about how long in terms off distance that's right and we do that force x distance it turns out we'll get a change in some other quantity and other quantity is not momentum it is begins with an e and RJ okay and this is what we got to talk about today what's time distance will produce a change in energy what is energy energy is that a numerical quantity which appears in many many forms like mechanical energy we talked about mechanical they really energy of position potential energy energy of motion motion energy we don't say motion energy music Greek word for motion because with the K checking in to see if your neighbors on what kind of what's with what's motion energy with k kinetic yeah kinetic energy okay and we can talk about later on we can talk about heat energy sound energy can anyone think of any other kinds of energy come on gang some more light energy enter a good radiant energy radiant from radium think like that huh thermal energy turns out energy of being it turns out everything has this quantity called Energy and that's given by Einstein celebrated equation later in the car we'll talk more about this the idea that energy and mass are two sides gang of the same coin you guys get smashed right you know what your mass is squashed up energy you are all bits of energy all squashed up if you want the more energy you have and sometimes you can convert from the inertia kind to the radiant kind and that's what happens when the sun and the Stars that's the interview Fusion we'll talk about that too but today we're only going to talk about the simplest kind of energy mechanical energy and its related idea work because this force x distance we don't call that impulse Ken X time is impulse we call force x distance another word see if your neighbor doesn't know what it is who came unprepared doesn't know what is a ball together at work equals a change in and I'll just put a for energy right if I'm lifting something up if I lift this block up I do work on the Block when I left it because I'm getting a horse through some distance okay. Hi I left it the more work I do the more work I do the more what it has begins with e energy okay if I Elevate way way way out it's got a lot energy and we call that energy energy of position and that energy of position you could you could put the work in today and you could use it tomorrow so you can store it it can be there for your potential use so that being the case gang we got a name for energy of position begin with p e what is it potential energy potential energy is energy of position we talked before about a slingshot when you pull a slingshot back further okay faster and we said it going to go faster to get more momentum today we're going to say momentum but that has something else begins with e ends with Drew it wouldn't bet that ends with y energy but now its energy of motion support the position more position position more energy or kinetic energy that's how about cannons how about you get a Canon like this that long can you fire a cannon ball out something but suppose you have another Canon same time I can only larger if I had the same kind of cannibal the same amount of powder out it goes in which case will The Cannonball go further how many say the longer one show hands how many say the longer one because there's more impulse on it Callahan's how many Subway in Empire was the other day today come on impulse what is impulse canning it's a force and the time during which it acts but couldn't we also say hey it's going to go further because there's more energy given to it how many see that even if the forces the same cuz over here hit with a certain Force here a certain fourth but he is a force acts over this distance what are the four sacks over this distance which is bigger this one or this one just wanted it so you'll get your doing more work on the Cannonball so it's going to leave with more kinetic energy we can kind of see if something got a lot of kinetic energy got a lot of momentum if I got a little kinetic energy are related they related it can be confusing sometimes we're not going to push that to death though just want you to know that when you do work on something you can change the energy that it has I can kind of show you that ball of hair there's a bowling ball from the ceiling on this bowling ball and increase its potential energy cuz what I'm going to do is I'm going to pull a bowling ball back it's going to take a forced to do that this little device here will show the force that I applied and we can look at this kind of close up and we can see that as I pull it more and more the forest gets more traitor traitor trailer varying with the angle it gets very complicated to multiply the force times the distance because the force keeps changing with a distance so to calculate that you need a kind of mathematics that we're not into right now call calculus but it turns out when I do that and I pull with an increase increasing decreasing Force higher higher higher higher higher I'll get a particular number here but you know what I've raised it this high off the ground if I simply set up straight up it takes more Force but I lose I go a smaller distance and guess what that greater force times a smaller distance is compared to the variable for x a long-distance take one guess what the energy is at the both ways now take a guess how many sitting next to someone check the neighbor what is a gang same-same that's right that's right I'll show you another nice thing this pendulum this pendulum illustrates one of the most important ideas in physics what I'm going to do is I'm going to hold this against my teeth and I'm going to let it go okay and you watch and see what happens I didn't Flinch man I do it again close my eyes I already at my icebox okay you know what what's this illustrating how many say it's probably not illustrating anything it's just bowling ball going back and forth energy conservation the idea that you don't create or you don't destroy energy you just switch / it from one form to another when I lifted this up at head energy of what begin with p position right and why let it go it turns into energy off motion Connecticut right until the position motion position motion position but here's the idea when I started I did work and looked at it to a certain amount a certain amount of energy called a thousand units when I let it go what's a little work on the wall okay but the idea it will never come up higher if it came up higher would have more than a thousand units and we have a little dictum in physics no can be but we've never seen such a thing never as anyone record it and verify the idea that something could put out more energy than was put into it we call that idea the conservation of energy pendulum this level is lifted and has a certain potential energy at this point of entry potential energy with respect to say this level that's how much potential energy maybe it's a thousand units called a thousand those by the way would be calling Jules Newton meter we're not going to get too much into the into that to do too deeply into that but say a thousand units of energy here now it goes enough room no more potential it's all what kind of energy game some people know the value of the kinetic energy there and some people don't Tinker sitting next to someone who do how tall is Ivanka how many cents a thousand I don't really know I don't mind paying attention and I don't know what it is. I want to go to the other side what will it be a thousand or not quite it turns out not quite boom energy yes or no as we go to the end account for the energy then it turns out when you swing it it never quite comes back to where it was you know why it's transferring the energy somewhere else guess where how's the temperature feel today again relatively cool how many say that's strange it seems to be warming up something's banging into the air and it bangs into that but when have the air molecules move a little faster and will learn later on the kinetic energy of air molecules honey we talkin about the temperature in so what'll happen cuz the interview go from that to the energy of the molecules in a room it dissipates in the form of heat but you always have it there it always adds up and that's kind of nice all the physics experiment to do what you always find out the energy score Remains the Same and sometimes when it doesn't seem to you discover things that maybe you didn't know about before it's marvellous a marvelous principle of physics conservation of energy calculate the energy of any system it's a Galaxy about to explode calculate the total energy what the Galaxy 2 what it wants to do a spin around if I don't care what event then calculate the energy in there again what are you got same darn number it might be different forms now maybe more like the before but the energy to trance count to one form to another and that's kind of neat what suppose we have the case of a person up at the top of a flagpole rough at the top of the flagpole and I got to dive into a little bucket of water please do this the circus is okay because a dude up here he's going to jump 10000 units of energy what is potential energy isn't it he's at rest so being at rest what would is kinetic energy be zero right into the bucket when you get down to the bottom of the bucket the potential energy is what 0 with respect to the ground so down he knows what the kinetic energy of a flat is I know you do that just double-check to be sure what's the value of the kinetic energy here how much kinetic energy how many people don't say 10,000 10000 unit halfway down the potential owners he's only have 5000 people can calculate with a kinetic energy must be see if you're sitting next to one what's it going to be in 5000 what 1/4 this 1/4 that looks like 2500 will the kinetic energy be more or less 75 touch that what unit is he the rule here calculate the heat of the bucket In The Heat Of The Remains and what you got 10,000 dissipate participate but it's always their energy score stays the same try some kind of neat here I've got a piece of metal I'm in a way it Tonka metal weighs a little bit more than 10 Newton's about 10 and 1/2 now what I'm going to do it with two scales and you guys tell me what's the reading going to be each day off this is. I'm coming over there 1 scale hair we had one more hands should be half gang is it half let me take this one off and at an angle it gets wild information overload today will only talk about straight up and down okay my cutting is a showing half so I can hold it up with half as much force when surprised the other side and left it okay but suppose first of all I do work and I left it like this I want to lift it but suppose I want to let that up to the 20-centimeter mark how high did I move my hand I move the bottom of this up centimeters how far is my hands more more less or the same did you say the same if you take that reading just about 10 and 1/2 in X the twenty centimeters number okay that's the number that's the amount of work I'm doing when I left it up okay it's going to take that amount of work to lift it up 25 minutes let me put that on the board the work I'm going to do as far as times distance is going to be it would let's round it off to 10 okay 10 Newtons and the distance I race it where it was 20 cm or 2% of tenth of a meter to centimeter and that's going to be equal to Newton meter and we call that a juul 2 joules of work lift it up 20% I'm going to look it up 27 to get in but I don't like having to pull so hard I don't want to pull with 10 new I'm getting tired I'd like to pull with about five Newtons how can I do that I could tie this on to here we have to wonder if the Ancients who constructed the pyramids knew about so simple and idea as we were talking about today because now I can lift as you've seen with half half the force half the force now I'm going to lift this up 20 cm and you watch How far am I hand moves with a 2017 Mark right here how far is my hand move more the same or less in fact how for how much more can you say twice as much I moved my hand through four tenths of a meter what the force is and it was only five Newtons but I had to exert it through twice as much and what's the results game 2 joules this is like the machine some people think that I'm a Sheen can change the amount of energy those people are wrong a machine can't put out any more energy any more work then put into it what a machine can do is change the force that's required to do that work so whether it's a pulley system or whether it's a lever the work you put in is the work you get out and you can hold a leveraged different positions and you could get different Force to do the same or no machine can put out more energy than is put into it okay what can it change see if your neighbor knows Empire State we can kind of see the answer to that we look at the equation for work work is what force x distance since the work input work output is the same what you can do as you can see flash back and forth between whether you're increasing force or increasing distance considered a huge truck the flat tire and that truck got to be lifted so the tire can be taken off can you imagine the Ancients back on the pyramid being built seeing a little girl using a bumper Jack to lift the mack truck a little kid and it can buy and it's sad to see the kid go and see the truck come up in the air did you how did you lift that truck and she's well I had to just do some work on the Jack and the work on the jacket work in the truck and then work on the truck same as a working a jack no big deal this is 20th century is this but I'm not 20th century yet could you ask send that to me when I push down I have to push a little Force but I thought I got to go what am I push X the distance I push the right number X how high is go in and guess how big the numbers are compared to each other game same same what if she went like this click click in the truck one quick quick Moorestown times the distance equals a fourth kind of different kind of show that like this before she might push it be like that and the for she lives might be like that but the distance she pushes like that and the distances Rises is like and these would be the same quite the same some of the energy goes into working and heating up the jack a little bit so this number is always a little bit smaller and how much snow will we get in the idea of efficiency won't talk about that but will I deal with ocean see this can never be bigger than this play walking down the street and see some some dude pull a pulley system on a Samsung you know that a human being can ever left one of the grand grand piano type jobs okay how to be such a thing well first of all if the pulley system the pianos being held by 10 ropes in a rotation be the same in all ten bearing friction his friend he's pulling one of those tensions the same as those so he's got one-tenth the weight of the piano so The Piano Guys a thousand people's a tenth of a thousand what's that a hundred he can pull a hundred but for the more you multiply how many meters are Roll dance by the force he pulls you got to know multiply the weight of the piano among that time times the amount of meters it goes up smaller number you multiply those two together what's the biggest number can be hey sunshine it works it works energy I remember years ago I used to hear people talk about the so-called conspiracy at the oil companies that the cars automobiles with little gadgets usually involving magnets attached to the carburetors of the cars would allow cars to go fantastic distances but the oil company have fun at the patent and I was holding it from the public so the public will have to guzzle down more oil make more money for the company's TV idea that maybe I was told one time for example with these devices want to put a couple of liters of gasoline in your car drive from Boston Massachusetts to San Francisco and a couple of leaders but the oil companies won't let you do it so you have to burn a couple of barrels or something like that well how about that game is there any are there any rules that govern answer begin with a y try it ends with a p right there is an energy conservation and let's talk about that right here okay we're going to push the car across country it's going to take energy to do that it's going to take energy to do work on the car and that work is the force times the distance that we're pushing the car. What's the force that keeps a car going even the straight road what's the forecast is the force against friction and for a very streamlined car that force can be something like a thousand Newton's 1000 Newtons at highway speed so let's see what happens what's the energy over here what's the energy given to us by the gasoline and that's a certain amount it turns out gasoline has an energy content of about 40 million joules per liter 40 minutes the energy thing means if you have 40 million units of energy to spend that's the energy content in gasoline what we're saying is these two numbers multiplied together can't be bigger than that cuz that's what you got to spending the gas tank I don't care what kind of gadgets you got that's it now how you going to do it you're going to push your car through some tests let's see how far you can push it how far can you push it will be pushing it up hill then take more Force those with smaller portion than downhill me to grab me to do it for you don't need me there okay on a level Road you got to push against the air dragon that Drew the faster you go the more direct and let's take a an average unit of a thousand a thousand Newtons of force and now we want calculate can we calculate Yang at our seats that's the one paper what's the distance that the car could go with a thousand units units of force pushing them on how many kilometers will the car go on that one calculator such thing now am I doing it right again am I doing it right if this times this week was at the Mystique was at / this is that right that's what the algebra we can do look at the zeros honey I don't even have a calculator how about without a calculator we can do one goes into 40000 how many times 40,000 so this car is going to go 3000 and it turns out if we express force in Newtons distance in meters and energy in joules the units will match so we have no conversions to make so this turns out to be 40,000 we don't say 1000 meters we say 40 km so it turns out to be 40 km you know what this means guy in a car that is 100% efficient you can't have that play the cat 100% efficient that means all the energy of the gasoline goes in the movie in the car and goes into the Heat and goes into the sound and goes into the upper limit you have to push with a thousand Newtons which is reasonable get nature Nature's ultimate is 40 km 40 km per liter play one way and get more how's that how can you get more distance by changing the force that's right if you can decrease the force then you can increase the dis is he there and how do we decrease the force with cars we make them streamlined so they cut through less Air drag is Damo and usually you're going to get about 25% efficiency which means 25% of this okay which means you usually get about 10 km per liter so what you're trying to do is to increase the efficiency but this isn't the upper limit the most people don't realize this people don't know there's an upper limit that Nature's limit and I think that little Gadget to something can help somehow beat this and many of the devices that are submitted to the patent office quote this all together and the first thing that what types of December taking the machine is it wait a minute is it going to violate the conservation of energy if it does we don't want to look at it and the reason is the patent people have looks 1,000 and thousands and thousands of ski maybe hundred and hundred hundred schemes which all seem to give you a lot more energy than before and they find out with a little fly that so at this point I just say look if it violates energy conservation, it's another wacko wacko because nothing has so far shown that you can get more out then you put in so there are rules to the universe and that's one energy conservation you can change from one form to another but you can't get more than you started with no free lunch deck it would most machines you don't even break even cuz some of that energy goes into overcoming friction turns into heat so why didn't you get corn flakes in the morning guy you can't eat your corn in the morning is what do you do those things are being torn apart in your stomach and it's 125 the bonds that energy becomes part of guess who and you use that to go about your day and what happened you stopped eating how long can you keep running your car without putting gasoline it how long can you keep running your body engine without putting food in so the conservation of energy a biology for right underneath I need little device here so generator consists of magnets is magnets and inside here I have a coil of wire and I'm going to turn that coil of wire and the coil of wire is going to turn inside the region called the magnetic field and when it does that it's going to induce electricity and when I do that I can like the lamp how that happened we'll talk about in the course but for now we can look at this in terms of energy that light that you saw glowing that's a form of energy what was the source of that energy it was the Corn Flakes this morning because it takes I have to work on this if I want to make it brighter I got to work more okay later will around me imma keep turning this thing we could generate electricity to light up cities and sure enough we do and we have devices like this we put a waterfall over here and turn it use the energy of the waterfall potential kinetic foam rotational mechanical do that or we could put a steam turbine here direct some expanding steam against the turbine against a Paddlewheel and turn it and so our civilization really rests on two devices like this but there's got to be some energy input to be transformed now here's a neat little I turned it and I unscrew the lamp it becomes easier to turn easier to turn when it's cooked there's no energy going off and so while I'm turning I guess now is a fraction but when it's hooked up I'm pushing against the friction plus the electricity so much show me the volunteer could you come up here please what I'm going to do is stand over here and what I want you to do is I'm not going to look over here okay and I want you to unscrew that and I'll tell you when it sounds screwed cuz I'll feel better over here so let's tighten up now okay okay is it true screw you. Now it's on how do I know I'm looking right up here take it easy pacific at Target how about now okay is that so I can ask the handle knows what the lamp is on how about that what's going on there again even why they're having some mechanics at why that happens we going to get up to when we get up to Electra GM magnetism delicious stuff okay or we see that energy consider it an attack bonus it takes energy to light the lamp that being the case let me ask you a question you get your car you want to find out what your gas mileage is cuz you want to compare it with stanced cars you all got a contact so Sprint is bragging about getting so much mileage that's so much mileage you want to test yours too so you're driving your car and you drive along the highway it looking at the speedometer is he on my house you go tank it up later and see how much gas do I have one of the other let me see how many miles per gallon you got how many kilometers per liter yeah and you're doing that and you're driving along and I just doing that someone reaches over and turns on the radio and pulls out the light switch and pushes them a cigarette and you say what you cut that out you're screwing up my gas mileage true or false check your neighbor what's the answer guy give me the app and will also Olivia with T ends with R O which one how many Saints Row how many say hey when are you driving night time if you want to save on gas what should you do what's your lights off how come you're driving with no lights in front to save gas true or false that's true that's right so I want you guys all learn something from this course I don't driving another device on driving the lights off right now but nevertheless you are burning more gasoline when you put your lights on see if your friends know that probably a little probably a little but you really are there's no free lunch I think that's just hooked on the drive shaft anyway it doesn't know the difference did this know the difference when it's was on it and always the difference it's got to push its got to do work you're going to burn a lot more gas air conditioner on you know why especially on a hot hot day because now you having to put out more energy to get through to 22222 air condition the car more energy how we do that we going to be talking about later that night let's talk a little bit about kinetic in I haven't given you the relationship for kinetic energy yet let me give it to you little tricky I'm not going to drive it it's driving the footnote in your text I'll just state it without proof if half the mask * the speed square remember momentum was just mass times speed simple simple or complex speed square the square of the speed tells you that wow it really depends on speed because it's speed X speed so it's very very speed dependent when we talked about firing the rifle before what the momentum of the bullet equal the woman on the rifle coming back so momentum momentum same impulse impulse saint but that was kind of father some to some people cuz this is got something more than this and you know what has more energy okay because your speed but now with energy is squared who so the Bullet going out might have the same momentum as like I'm coming back but honey most of the energy that is in the bullet not the gun cuz we're squaring that greater speed you square the speed the results of giving example you're driving down the road and your car and you're going 30 kilometers per hour and you you step on the brake you're going to change your kinetic energy you're going to change it in the kinetic energy you have at 30 km per hour down to zero What's it take to change that kinetic energy game it takes work and that work is what what kind of way stop your car we can let the equation guy. Thinking it's a force and it's a distance distance is this is your car skids yeah and the force must be the friction force of the wheels against the road yeah okay okay so that's the friction Force that's the distance okay now we repeat we go twice as fast to get twice the momentum we go twice as fast we step on the brakes we skid to a stop we scared further some people that work twice as fast you going to get twice as far how much for a chapter neighbor did the neighbor knows already prices for asking how many state twice as far as a more than twice how many can calculator to be f o u r x four times as far as it turns out the fridge Forest won't change with speed how much the crowd the tires in the road grab each other does not have to do is speak the same friction not the same friction is going to drag you four times that's why people going to lose it when first learn to drive you got to pick this up Savvy wise you know you got a little bit faster than the brakes in the surprising at first that while it took so much longer to stop are you that caught up to three times as fast now three times a speed okay so not 30 butt 90 kilometers per hour now with three times a speed you know you got more energy more kinetic energy some people know how much more check with a neighbor how many say 9 times as much energy that means you're going to ask it how much further nine times as far as right to get the idea so kinetic energy is velocity dependent Square drop a ball game when I dropped the ball it'll never return to the same height why potential kinetic potential but there's a little Gap what's the Gap and potential energy where is that energy going now find the Heats going to warm up the table warm up the ball so you never can get a ball that will bounce as high almost but not quite here's a little device it's kind of nice it's a portion of a Racquetball and I can invert it when I do that I'm I doing it a little energy I'm going to drop this and watch did you see that it bounced higher than when I dropped it H C and here's another question to will it always bounce higher from where I drop it if I got higher up with it still bounce higher where is the point where it will not bounce higher anymore and why think about that good show me another joke Super Bowl the Super Bowl and let it go some people think of Super Bowl will come out to the same height but it won't it comes up to about live at 1 the Super Bowl is guaranteed to give a thousand pounds we got this this morning Troy's been playing with Troy how many pounds did you get on it 990-596-9798 okay what's a 900 99 1000 sure not that's true I tried again its elasticity is gone game think about that catch you later cuz

Video Gallery

Energy Ch#5 Paul Hewitt

Popular Videos