High road low road race, potential kinetic energy Part 2--Homemade Science with Bruce Yeany

[@sachiperez]

Why do I find this fascinating? I have no idea how to apply it in my life, but it still blows me away... Thank you Bruce!!!

[@danielharman4437]

Who else wishes Bruce was their science teacher!!!???

[@ezradelsman6743]

Daniel harman me

[@explodinglegos99]

Daniel harman everyone does

[@tuckerbonawitz1819]

Exploding Legos he is my teacher

[@explodinglegos99]

Tucker Bonawitz where does he teach?

[@ianmacfarlane1241]

Daniel harman You would probably be surprised about that stuffy teacher you had tears ago. Appreciation of your teachers sometimes comes with age. For the record I had a wonderfully eccentric madcap physics teacher at school - Mr Barr - a legend.

[@TimA-kf1qv]

videos like yours make KZbin worthwhile

[@ConstructionMachineryChannel]

Bruce, these are great demos! I'm so glad I found them. I can use them with my classes when/if school resumes due to coronavirus.

[@stevegraydon6351]

Love this. I will not be able to think of cycling the same ever again...

[@Gruuvin1]

Bruce, your videos are so excellent! I bet you are the world's best science teacher! Thanks!

[@davemarx7856]

Thanks for revisiting this experiment. It's great how the simplest concepts can create so much concern over the slightest variations. It's Science at it's best.

[@drewmi-x6l]

Very nice video! Liked the discussion with the hills getting too steep. I also like explaining this by discussing that the normal force on the downhill sections increases V_x. So the average V_x is higher for the bottom track and since their horizontal lengths are the same, it must take less time.

[@mattbates3203]

Thanks Bruce. Passionate and interesting demonstrations/practicals are what makes science fun!

[@LiftPizzas]

I loved the illustration of rotational energy being used to get up the hill. The slowmo of the ball spinning out at the top of the hill was perfect! The high/low road thing ties in with the brachistochrone thing too, which vsauce and Adam Savage did recently. (I like your design better, looks like you don't need a bunch of expensive equipment and supplies to make your own.)

[@Nikkikkikkiz]

trigonometry

[@meeintiabbayi729]

i learnt so many things 'coz of u .I tried my knowledge in my college .they were surprised a lot .thank u dad .i love u ☺

[@pastramichop]

the Vsauce youtube channel recently uploaded a video about Brachistochrones and the geometry similar to what's being shown in this video

[@AlexE5250]

Don Williams I was waiting for him to start talking about brachistochrones!

[@PlanGIV]

Great explanations, thanks a lot Bruce!

[@maximuz976]

The Kinetic/Potential energy was one of my favorite subjects physics class in school. Amazing illustrations made here, loved it.

[@daboo123]

I learned a lot from this video. I wish my teachers were this good at teaching when I was in school.

[@VeteranVandal]

You are an exemplar teacher, mate.

[@YeanyScience]

thank you, I appreciate the comment.

[@M_0892]

Thanks for posting these videos. It makes science experiments so much more available and inspires people to do there own experiments. Please keep on posting and thanks once again!

[@YeanyScience]

Thank you MIchiel, I have more planned

[@agostinhooliveira3743]

As always an extremely interesting video. Thanks Mr. Bruce!

[@woodsmatful]

Although it is common knowledge. I like to see you making it fun and visual. Especially for younger minds.

[@PushingThroughThePain]

This is amazing to watch! I never had anything like this in my highschool, and I really wish I had. Thank you for being such an amazing teacher and for putting these lessons on KZbin! Your students are lucky to have you!

[@TedOfNod]

This guy’s got balls of steel! ✊

[@DrToonhattan]

So what you're saying is that if you take the high road and I take the low road, then I really will be in Scotland afore ye?

[@chrishamilton8134]

DrToonhattan , I think he is proving that in any religion, and any gods word, the point is , the High Road may take longer, but has way less bumps in the Road. trust in your God and you will get there, take a short cut. . . at the end of the video, the hill may be too steep. . . . and you end up in the bottom. . . . J.S.

[@bennylofgren3208]

DrToonhattan I'd prefer the road less travelled.

[@tylor_vwricer]

DrToonhattan *lock lomond intensifies*

[@davemarx7856]

will watch tomorrow ASAP. Thanks for revisiting the test.

[@microbaltik]

Awesome !!! Thanks for the whole demonstrations !

[@whatyousaidbud]

thanks so much Bruce, you answered all the questions I had thought of and some I hadn't!

[@Bikewithlove]

These friction/energy principles actually come in handy for everyday driving, in terms of choosing certain roads and shortcuts based on their distance and topography to determine the quickest route that will also save the most gas.

[@Bikewithlove]

@theory816 - Was it everything you hoped for?

[@anullhandle]

@@Bikewithlove given your screen name assuming moto, the route with the most curves wins :) Note the quickest route, shortest route and the one that uses least fuel might well be different.

[@FencerforJesus]

These are awesome. I just discovered these videos and I teach AP Physics. I'm planning on building these and maybe coming up with some of my own ideas to go with it. One challenge for the AP students would be to see at what time do you need to give the high track ball a head start so they get the same end result. Great work. I'll be checking out your other videos too for other ideas as well.

[@JeremyMcMahan]

Bruce, I appreciate your videos greatly! I can't wait until my children are starting to learn about physics (they're still pre-school) so we can binge-watch your videos together!

[@YeanyScience]

Thanks Jeremy, by that time I think I will be retired but my videos will still be here, I appreciate your comments

[@anullhandle]

So here we are 4 years later. You might not be in the class room but you're still teaching! :)

[@unknowncuyler5449]

@ 3:44 i know you clearly know the answer to the question you pose. you dont even tell what you know about this. this is what makes you a great teacher. telling me the answer doesnt teach. showing me so I come up with it myself will. if only all teachers understood this. we would have a much more intelligent population today. thanks for another great video Bruce!

[@SpeedieGT5]

mr Bruce, you should've watched VSauce's channel. he made a video not long ago about the brachistachrone, the most optimal curve (a cycloid) for this problem, really interesting. So it shows you the solution of this question you're having.

[@snowwhite3212]

Amazing...I knew this video would be good

[@IndependantMind168]

Great Job Bruce.

[@YeanyScience]

thanks

[@TheObserver100]

An analogy to life is that sometimes going through ups and downs in life gets you further than a life without obstacles

[@kipperkell]

Hey Bruce! I was watching some of your videos and my partner thought I was watching a Kevin McDonald skit because she says your voices sound the same! I didn't agree at first but now I can't stop picturing him when you speak!

[@YeanyScience]

Great, now I hear it too

[@thepushyguy1386]

Love these tracks, great videos!

[@carultch]

You inspired me to build a high road/low road track, along with a hump track that was as close as possible to the low road track with the essential difference being a hump to the high road level. I got an interesting result when I tested it with golf balls, while I'm waiting for my mini billiard balls to arrive. Interestingly enough, the ball on the hump track beat the ball on the straight low road track, much to my surprise. This result only happened with the golf balls, since I've also tried it with gumball machine bouncy balls, and in that case, the low road track ball beats the hump track ball, as I would expect. I think an explanation of this result might have to do with some resonance of the normal force on the ball with the elasticity of the track material, that propels the ball forward on the hump track. The hump track ball has varying normal force, unlike the straight track that has constant normal force equal to the ball's weight. The track contains plenty of spanning shelf material, that could easily vibrate.

[@alexgreader]

that is actually really cool!!!

[@Holobrine]

You should build a brachistochrone track. Or maybe brachistochrone on the sides and flat in the middle to make it longer.

[@anxez]

You know, your videos are kind of pedantic sometimes, but the science is always intriguing.

[@YeanyScience]

I guess that's how teachers get sometimes, I try to give it my best shot

[@anxez]

You're doing an excellent job. And take what I say with a grain of salt, obviously.

[@jumperjackflash]

This was a fascinating video. Thank you.

[@Moraren]

Have you watched Vsauces video on the Brachistochrone curve? If not, do so! Its a bit related to this!

[@samsimons1105]

Moraren yes! i was amazed by that video!!!

[@samsimons1105]

Moraren i likes how they all ended up at the finish at rhe same time

[@yadeliztexidor6183]

I love this!!!!!

[@how2pick4name]

If every teacher was like this, nobody would have an excuse to be stupid. :)

[@pohldriver]

Smart truck drivers use these principles all the time in the mountains. If they're loaded heavy, but have a smaller electronically governed engine, they are said to have a "dragonfly" truck because you're dragging the truck up one side of the hill, and flying down the other. Doing this, on less curvy hills with a clear line of sight, reduces fuel consumption, is easier on the truck, and keeps your average speed up. Now, there are some hills throughout the Appalachians that have escape ramps for trucks in the event of a mechanical failure or for rookie or arrogant drivers that font pay attention to the road signs. They end up going too fast and over heat their brakes, making them useless or even setting them on fire. I saw a picture someone posted the other day of someone who's trailer brakes failed. the brake drums had to absorb so much energy that they were literally red hot.

[@SirButterHead]

Wow. I feel hypnotized

[@edwardholmes91]

Another great video Bruce, it would be interesting to plot the distance, speed or height of both balls on different tracks against time. I'm not sure how you'd accurately measure it... other than using speed gates all the way along the track maybe? They would need to be synchronised with the same clock though, so might get complicated to build. Perhaps just analysing slow motion footage would be easier?

[@YeanyScience]

We'll try these again come next school year, I have a few ideas that hopefully will examine a bit more accurately what's going on. If not, the slow motion camera always helps. thanks

[@mohitsoni7545]

Question on this topic came to my jee main mock test that time i made it wrong but now it's very clear Thankyou so much

[@billbrown994]

Very interesting Bruce. Cannot wait to see the video detailing how to make these? Has it been made already?

[@YeanyScience]

send me an email at [e-mail] for more information

[@alexandrebaraka1]

love this video. I love mechanical energy

[@Drackeye]

Forgot KZbin removed the DM feature so I'll post this here. I really enjoy your science videos and have started incorporating your videos into my children's homeschool lessons. My children seem to really like your videos too. As this school year draws to a close, even for year-round students, I know it's a little late to ask this for this school year. However, I was wondering if you, assuming you have the time, would be willing to draw up some short quizzes based on your videos for my children for the next school year. Preferably the videos prior to your retirement from formal teaching in school. While I can create the quizzes myself, I feel quizzes from a certified teacher would be better structured and thought out. I do understand creating quizzes is a time-consuming endeavor and, as I have no means to reimburse you for your time, do fully understand if you decline my request. Thank you in advance.

[@YeanyScience]

thank you for your interest. I've always hoped that the ideas in my video can be a starting point or reference for other school teachers as well as for those homeschooling. While some of the videos are better watched than tried, I would hope that students get to try for themselves many of the projects and investigations that are shown here, The videos are meant to supplement lessons with some activities but I would suggest they be taken further than I've shown them. I can offer some advice and questions on many of the concepts specifically on my pieces, There are also many other resources that offer complete lesson plans, activities, and testing information. You can contact me at [e-mail]

[@chrishamilton8134]

good job , I enjoyed watching my childhood theories be proven in video. . . and please ignore the C.A.V.E. people , Citizens Against Virtually Everything. . . . you did good. please continue to teach.

[@chrishamilton8134]

sry, had to replicate, "" . . . " I think he is proving that in any religion, and any gods word, the point is , the High Road may take longer, but has way less bumps in the Road. trust in your God and you will get there, take a short cut. . . at the end of the video, the hill may be too steep. . . . and you end up in the bottom. . . . J.S.

[@YouAdrianziom]

Why there is almost no such cool teachers in school

[@ronaldmahan8417]

Because they get fired for not teaching the book the way the book says. Happens all the time.

[@willempl6400]

Another explanation if the 'spontaneously' running back and forth ball could be that the weight centre in the ball is not positioned in the very centre of the ball. Looking forward to your considerations on this issue!

[@72d]

Hi Bruce, I was just wondering would it be possible to buy any of these ramps?

[@tornadofay]

thanks. very nice explanation.

[@Kratax]

That clarified, thanks. Now I thought this about the balls stopping: The ball at the lower level has shorter track to go back and forth when it is stopping. What if they both dropped to lower level, but the other more low than the other, but both lower levels had the same length? I guess the lower would still move longer time until stop, because it has more kinetic energy.

[@prashantgarg6995]

that's how every physics should be

[@spagbollo5688]

The reason the tracks with more humps in were closer is because of the time the ball spends in the lower position in the low road track right? I think that's because the kinetic energy stores are increased on the low points so the high speed is present there.

[@airwatching2]

Beautiful, brilliant. Just subscribed.

[@wspollack]

1) Very enjoyable and educational video. Thanks. 2) At the 6:56 mark, could you change "... due to it turning around it's axis" to "due to its turning around its axis"?

[@YeanyScience]

I know, but to change it I would have to delete the video redo it and I don't have access to the area where I made it 8 years ago.

[@ianlaw1160]

Love this channel!

[@YeanyScience]

thanks ian,

[@desidudes78]

Fantastic video. I do have a question, though. During the test at 9:17, I would argue that the track with more humps reaches a lower height at the end of the track due to a LACK of friction. My reasoning is that due the changing relationship between the weight and normal vectors (the rollercoaster "g-force"), there is time for the ball to slip on the track due to a lack of friction which loses the rotational energy acquired. Thoughts?

[@brandonw409]

I'd be curious to see the same tests using tracks of the same length. I understand the difference in length was not that much, but we are talking about science here. In the test at 8:47, the ball on the high road track went up to a higher level than the ball on the low road track. But, we know the low road track actually has a longer distance to travel. I understand the argument of friction on the ball, but are we sure there was actually more friction on the ball just because it went up and down some hills? or was it because it traveled a slightly longer distance?

[@Broskidile]

Hi Bruce! Big fan of your channel, I've been watching for a while now. I had a question I was hoping you could answer, potentially in video format: My girlfriend and I play a game every time we go to a restaurant where there is straws. We each take one end of the straw wrapper in our fingertips, and each of us pulls. Whoever gets more of the wrapper wins... It's the same idea as breaking a wishbone. I was wondering if you could figure out any strategy behind this game, or a reason why the wrapper breaks the way it does? Thanks! :)

[@themsjosiah]

thank you so much Bruce I love watching your videos with my kids then we try building them working on the string thrower right now. what did you use to bend the track (I have not looked at the material) I know your making a video don't know if I can wait.

[@YeanyScience]

HI Mark, you can easily bend it by hand, I suggest running some light sandpaper over it before you use it. I buy mine at Home Depot, it is about $3.00 for a 6 foot section

[@themsjosiah]

Thank you too easy!

[@jacobperechinsky4257]

I like your experiments

[@jimmysanchez4558]

In the friction test it showed us that the track lengths are even closer then we thought because the low road ball doesn't travel the whole distance

[@jimmielegs]

This is so great! I work in a small museum in Iowa and we wanted to build the first set of tracks. Would you happen to have written/drawn out plans for the wood parts? Thanks!

[@YeanyScience]

yes, send me an email at [e-mail]

[@gonzalopinedacarmena8938]

Proffesor, first of all, thank for your videos. I really like them a lot. I have a question: did you say that if you clean the ball you will loose drag needed to continue rolling?

[@YeanyScience]

yes, some of the ball's energy is turned into rotational kinetic energy, if the track is steep like the large one shown, the ball needs traction to be able to change that rolling energy back into movement up the track. If the ball is polished, it loses traction and slips like it is shown in the video and can't climb back up to the top.

[@schitlipz]

Very neat. How does a parabolic drop compare to the straight one?

[@willempl6400]

Hi sir, thx for posting this video. I noticed something that highly surprised me. When you tested which ball would stop moving first, the one at the highest road ended on a horizontal part, which is quite understandable. Yet, what I do not understand at all, is that this high-track ball with its last energy twice returned/changed direction while it was on a horizontal part/track, and did not even touch the slopes at either side. That is peculiar, no? It would mean that moving object kind of 'remember' the very moves they made before, for this forth and back movement could not be caused by either gravity kinetic energy nor rotating kinetic energy. Looking forward to your reply!

[@YeanyScience]

I noticed that also, I checked the track and it is straight, maybe the table on a slight slant. I will try it on the same table and see

[@willempl6400]

Bruce Yeany Well the first change (at 6.01) could be caused by a slanted table, but then howcome it changes direction again at 6.03 ? I guess there must be a slight pit in the track. Or can you think of another explanation?

[@nrous1717man]

After watching the vsauce video about the brachistochrone, I have a much deeper appreciation of the math and physics behind this :)

[@YeanyScience]

It was excellent

[@slawdify]

so many variations. i think you may want to consider comparing for example the 1 hump to 3 hump etc. the high road point was made but there's more to discuss/complicate with low road variations. great work nevertheless

[@pierre-henrifrancois1674]

very instructive video! even for experimented engineers... ;)

[@mayathemaster]

There is something that I dont understand. At the end, the slope tracks both balls have the same height differential between start and end. So the potential energy is the same for both balls at both ends. Though one of the bass has more kinetic energy than the other because it moves faster so there is some extra energy that I am missing out.

[@LeParkourarte]

Hi, Bruce! You should make a loop in the tracks and explain how it works :D or even a double loop

[@YeanyScience]

HI Alex, it's on my make list

[@VenturaIT]

@@YeanyScience They don't actually end at the same point on the x-axis if you look closely (mid-way or end-point, whatever you want to call it...) the slower ball is going further along the x-axis, just slower... this is the law of conservation of momentum... the faster ball is going less distance along the x-axis, but with more quickly... you can adjust this by changing the moment of inertia of the balls and the radius of the balls... changing the mass will only change the friction and make the heavier (more massive ball) go more slowly... it's much like gears, or pullies...

[@KcDaugirdas]

My question is, "what about Low road vs. Low-ER road vs. SUPER LOW road?" Is there a limit or optimum amount of drop in the track to achieve the fastest travel time?

[@uualrus]

What if you set the flat track as "x=0" and then made a track that went both below and above the x-axis would the curved track still win? If you made the area under the curve zero for both tracks I would predict they would both reach the end at the same time

[@charleswatts1864]

Nice test! Did you build the tracks yourself?

[@YeanyScience]

Yes, pretty much all the pieces in my videos are homemade

[@TheOriginalJphyper]

My town has an activity center with various exhibits demonstrating various scientific principles. This phenomenon is one of them. In addition, Vsauce just recently put out a video about this as well. The video goes into detail about the optimal shape that a track needs to be in order to maximize the acceleration gained by this phenomenon.

[@beliasphyre3497]

Fascinating.

[@jordanlapointe8207]

Belias Phyre agreed!!

[@bearminator90]

So let's say you start both tracks at height 4 and let them fall at height 2. One of the track is straight and leveled at height 2 until the end where it reaches height 4 again. The other track keeps going up and down from height 1.5 to 2.5 (an average height of 2) an even amount of times until the end where it reaches height 4 again. The balls should arrive ideally at the same moment, am i right ?

[@ofekp]

You are amazing!

[@unlovable2613]

Made a 100 on the test we did on potential and kinetic energy

[@JollyJoel]

Michael and Adam from Vsauce and Myth Busters just did something on this and they mathematically found the perfect distance. (EDIT) It's called *The Brachistochrone* really interesting and so is this video.

[@YPOC]

So is there a cross-over point where the track that dips lower will take more time due to its increased length?

[@LordofStarsChannel]

Nice video! I just wanted to say these were not golf balls but ping pong balls^^ nothing important keep up with the great vids

[@therealmorty7158]

Mr. Yeany, is there an efficient shape that will get the ball to the end of the track absolutely the fastest?

[@schwarzerritter5724]

Would it make a difference if you used cars instead of balls? The polished ball experiment shows rotational kinetic energy seems to be an important factor in this, but with a car only a fraction of its energy goes into the rotation.

[@ericstender2150]

What did you use for the metal track? Where can I find the track to make my own? Palister (shelf brackets for shelving...Menards)?

[@YeanyScience]

metal shelf bracket tracks, they are available at building supply stores, hardware stores

[@shekhowong5551]

Bruce, thanks for the great video! After watching the video, I am curious if I drive the car on the hills, can it act like the balls case? And how to determine the velocity it need for the car to climb on the upper hill?

[@iknowyourerightbut6246]

It is like comparing between travel time on road, one is 35mph speed limit which is less distance than, taking an exit, going up to 80mph, even though it is more in distance :)

[@ashishsawhney6196]

Hi Bruce, What if the balls are rotating about their axis in the vertical direction too?

[@KudM]

Hi Bruce! I really admire your work! After your previous episode I and my friend were trying to build this track, but we cannot find materials on it. Could you please give me link to shop where you found them?

[@YeanyScience]

Home depot, shelf bracket tracks, $3.00 for a 6 foot length made by rubbermaid.

[@typxxilps]

great esp. loosing friction after polishing

[@christopherhazlett4245]

Hello. I am a high school physics teacher and I was wondering where I could purchase tracks like these for my class? Thank you for your time.

[@YeanyScience]

These were all homemade, I don't have them for sale as I still use them. However, they are not hard to make, the track material can be purchased at building supply stores such as Home Depot. I would be happy to send you building instructions if you want them. email me at [e-mail]

[@ganeshpamarthy4412]

bruce, low roads seem to be more useful as they gave added energy to the objects, ...will it be feasible to develop such roads in practical for public transportation

[@kwonhyuckcheol2935]

Hi. Bruce. Thanks for this video. I have one question. In your ball track, youe are using th steel strip with holes. Could you tell me the reason you use such strip. Is it for the revention of slip of ball on the track? I did some experiments wih "Space Rail" butthe potential energy is not preserved that is the ball did not reach to the height it was dropped. Is this mean that slip should be avoided for these kinds of ball experiement?

[@YeanyScience]

Whatever device you look at, tracks, pendulums bouncing objects, objects will never reach the original height due to friction but with small amount of friction it can get close. The steel track has holes in it due to that is how it is manufactured. The track angle cannot be made too steep otherwise the ball will slip, especially smooth surfaces without much friction such as the steel ball on a steel track. Increasing the friction between the two surfaces will slow the ball done quicker but the ramp can be made steeper so it's always a trade off.

[@kwonhyuckcheol2935]

@@YeanyScience Thanks so much for your kindness. ^^*

[@alexandermolberg5577]

That final track was it the orange or the yellow golf ball that had more velocity at the end

[@jeremygrecte]

What if on the lower track you put a higher bump ? The track would first go lower than the straight track, then higher than it (yet still lower than the starting point), then lower again and up to the ending point. Would it still be faster than the straight track ? Would it still keep moving for a longer time ?