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Episode Six 206 – Newton Must Have Been A Sports Fan
(Physical Science)
> Rick Crosslin: On this physical science edition of Indiana Expeditions, we’ll take a look at the science that moves us. We speculate that Isaac Newton must have been a sports fan. All in the name of physical science.
(Music)
> Rick Crosslin: Let’s go check it out. Come on!
> Announcer: Indiana Expeditions with Rick Crosslin is made possible through the generous support of the Dr. Laura Hare Charitable Trust: enhancing Indiana’s natural environment through preservation and protection of ecologically significant natural areas and promoting environmental education, stewardship, and awareness. The Center for Student Learning, Indiana Department of Education, and Veolia Water Indianapolis; as the operator of Indianapolis water, Veolia is dedicated to providing billions of gallons of clean, safe, drinking water to nearly one million customers in central Indiana every year.
> Rick Crosslin: We’re at the soccer field today, and we’re learning about how objects and people move. In fact, there are actual laws of motion. It happened maybe in the 1640s when a scientist worked these laws out. This is a big clue as to who he was.
(Music)
> Rick Crosslin: Isaac Newton was a scientist. You know the guy you always see getting hit on the head with the apple.
Isaac Newton in the 1640s in England worked out laws of motion that applied to a soccer ball or a big object like our earth. These three laws are quite simple.
Law 1: An object at rest will stay at rest unless acted upon by a force. Also, an object in motion will stay in motion unless acted upon by a force.
Law 2: Acceleration is produced when a force acts upon the mass of an object.
And my favorite, Law 3: For every action, there is an opposite and equal reaction.
We know that because of gravity, what goes up must come down. We know, thanks to Newton, sometimes when an object goes down, it comes back up, like a yo-yo.
Sometimes yo-yos don’t just come back, but go side to side and through loops. If so, you’re talking about my friend Kyle, the yo-yo pro at the Children’s Museum of Indianapolis.
Kyle, I’ve just seen like thirty tricks. Not only are you good, but you’re fast!
> Kyle Pearson: The yo-yo is a world affair kind of thing. It’s actually, the second oldest toy in the world, first being the doll, the next is the yo-yo.
> Rick Crosslin: Even though he’s doing these yo-yos, there’s still one thing that all these tricks and all these sports have in common, and that’s the physics that Isaac Newton worked on several hundred years ago.
Isaac Newton may not have played with this yo-yo, but the forces and the math that make this thing go up and down are still being studied today. In fact, they’re being studied here at Center Grove Middle School North. Let’s go check it out!
(Music)
> Rick Crosslin: We’re in Mr. Jeff Peterson’s class in seventh grade, and we’re having some fun with Isaac Newton and the yo-yo. You see, a yo-yo is a great way to apply all three of Isaac Newton’s laws of motion. But hey, don’t take it from me. Let’s listen to these kids as they explore science and have some fun with a yo-yo.
> Jeff Peterson: Newton’s laws of motion deal with everything that’s in motion, and everything is in motion. So the yo-yo, the kids can really see it in motion. We talk about all of Newton’s laws, so the first law of motion is an object at rest will stay at rest, and an object in motion will stay in motion, unless acted upon by an unbalanced force. And we talk about how there are really two forces in action. There is the force that they put on the yo-yo to throw it down plus gravity is also pulling down on the yo-yo.
We also talk about Newton’s second law of motion, once acted upon by an unbalanced force, will accelerate in the direction of that force. The harder one though is Newton’s third law, which is for every action there is an equal and opposite reaction. And so we actually use two yo-yos today to demonstrate that. One yo-yo is going to hit the other yo-yo, and it’s going to then transfer the energy over, and it’s going to keep moving in that other direction. We use books, and we use them as references, but we don’t just use books. I think a really good way of helping kids understand physics is by helping them to experience it. Having kids interact with the material as much as possible and helping them experience the hands-on activities is really the cornerstone of making really good science.
> Rick Crosslin: Forces, racecars, Indianapolis, and Newton’s Laws? I think I know where I’m going next.
With the amount of physics going on at a racetrack, Newton would definitely love racing. We went to see a tire test at the Indianapolis Motor Speedway, and to hang out with our friend Julian from the Chip Ganassi Race Team, and learned a little bit more about the forces and physics involved with their cars.
It looks like today we’re at one of the coolest science experiments around. Tell us a little bit about what’s going on back here.
> Julian Robertson: What we do is we have the control tire, as we call it, is the tire from last year’s Indy 500 or 2008. We only have one variable at a time. First we run through different constructions where we keep the same compound or rubber on the tire. Then we have a control tire where we keep the construction the same and change the rubber or the compound on each tire. From that, we pick the best combination and compare that against our control tire to try and produce a better combination tire the next year.
> Rick Crosslin: And I guess you keep lots of records. So your science journal is your race journal.
> Julian Robertson: Our race journals are very sophisticated. There are literally hundreds of things you can change on the car. So we have all that specified. And in addition to doing it with the tires, we get some time at a task like this where we change variables on our car. And again, it’s how well you do the experiment.
> Rick Crosslin: Let’s talk a little bit about the forces of these tires. Why do you need a really good tire in a racecar like this?
> Julian Robertson: We need grip from the tire to go around the corner as fast as we can. We need to generate as much force as we can from the tire. We do that with the tire rubber or compound, the actual grip of the tire, and the whole car is designed to give aerodynamic down force, which is a vertical force downwards through the car to push it onto the track. And we have three or four major components that have the biggest effect. The rear wing is one. This is like the wing of an airplane. But instead of on an airplane where it lifts the airplane up, we actually put it on the car upside down to push the car down. It’s exactly the same as an aircraft wing in principle.
> Rick Crosslin: The rear wing has down force. You say the actual body of the car does also?
> Julian Robertson: Yeah, the underneath of the car which we can’t really see here is shaped like a Venturi, so as the air passes through it, it speeds up as the Venturi constricts it down and produces a low pressure which sucks the car onto the ground also. And then we balance all of that with a front wing which again is a front aerofoil, like an aircraft aerofoil just flipped upside down. And we change the angle of this so that we balance what we’re doing with the rear wing. Because if you put all the grip on the rear, then the driver wouldn’t be able to steer it if you didn’t have grip on the front. You need a balance of front to rear grip to make the car go around the corner.
> Rick Crosslin: Now I see other little subtle things on it, like these mirrors. They look like they’ve been designed to be aerodynamics. Is that true also?
> Julian Robertson: Yeah, they’re really sculpted. We’ve put hundreds and potentially even thousands of hours in testing different mirror shapes.
> Rick Crosslin: So basically, if you have all of these down forces, when you go up on a curve, that holds you against the side of the track. How high up can you go on a curve?
> Julian Robertson: Well, the car produces enough grip that we could actually drive around on the ceiling, completely upside down quite happily. Maybe someday somebody will do it just to prove it can be done. But it would be relatively easy to drive around on the ceiling as long as you kept your speed up.
> Rick Crosslin: If you kept your speed up and had your down forces. This is all a balance between Newton’s laws, friction, and our friend gravity.
Well today, we’ve been investigating how things hold on a track and how things accelerate, but Newton also had some laws about de-acceleration. So let’s talk about what happens when you come to a quick stop. What do we have to keep the driver safe?
> Julian Robertson: There’s a lot of work goes into these cars on safety. It’s all designed and it’s crash-tested, run into brick walls and that kind of thing to make sure it behaves in a proper manner to absorb the energy to stop it going through to the driver. We also have what we call a crash box, which is supplied by the Indy Racing League for Indy cars. That’s soul purpose is to record the G-signature or the acceleration signature when you have an accident, so they can look at how well a car stood up to a certain magnitude of accident. By measuring the forces, you can kind of categorize, oh this was a really big accident. Let’s look at what happened. And it records exactly what the car saw in terms of forces. You can look at how it was damaged and start relating the two, and improving its response to those damage situations.
> Rick Crosslin: You know, I tell you, Isaac Newton would have loved to hear you say what you just said about G-forces and mass and acceleration, because he worked out the math of this hundreds of years ago, but I don’t think he would have ever dreamed that one day a red car like an apple, would be out on the Indianapolis track putting these things to the test.
> Julian Robertson: It’s all still the same math as he dreamt up all those years ago. It’s just been expanding its uses since then.
> Rick Crosslin: That’s amazing. Well Julian, I can’t wait to see this out on the track. We’ll put all your work to the test today.
(Music)
> Rick Crosslin: Wow! Law 1: An object at rest stays at rest until a force acts upon it. That was a big force!
We’ve been out to the track to see how fast these cars go, but now I get a chance to visit one of the coolest science labs in the whole United States. I’m here at Chip Ganassi Racing and seeing the science to make these cars go fast. Hey Julian, how you doing?
Julian Robertson: Hi, good thanks.
> Rick Crosslin: Well, what do you have going here?
Julian Robertson: This is the Indianapolis race shop, where we’re working on, this is the actual gear box shop we’re in at the moment. We’re working on ways to make the cars faster.
> Rick Crosslin: So I’m looking around here, and I see some pretty cool things. It looks like there are projects everywhere.
Julian Robertson: Yeah, we run the different cars out of here. We run Indy cars. We run the Grand Am Sports cars. These guys in the gear box shop work on gear boxes for all the different kinds of cars we run.
> Rick Crosslin: So Julian, there’s a lot of activity going on here. What’s going on in this room?
Julian Robertson: This is where all the Indy cars and our Grand Am Sports cars come together. This is an Indy car like we run at the Indy 500 Indianapolis Motor Speedway. And it’s just starting to come together. That’s the basic tub the driver sits in. This is a completed gear box. We went to the gear box earlier where it was being worked on. This is a complete unit ready to go. We’re working on the bell housing there. Where actually, these parts will come together, and they’ll then come to form the complete car you see here.
> Rick Crosslin: Wow, these are starting to look more familiar like parts of a racecar. So what’s going on here?
Julian Robertson: This is the body work for each car. Each car has its own rack identified with a number. You’ve got the engine cover, the side parts, the under tray, all the carbon fiber parts that bolt to the basic cover of the car to start making it an aerodynamic whole. Everybody’s heard of fiberglass which is what you make boats out of and that kind of thing. That’s quite cheap, not super strong. Carbon fiber is super strong for its weight which is why we use it in molding instead of things like fiberglass. It needs a lot of man hours, because the way these things are built up is with sheets of carbon fiber.
This is the carbon room where we make carbon fiber parts like the body work we showed you.
> Rick Crosslin: I don’t see any carbon here. I see rolls of stuff along the wall.
Julian Robertson: Yeah, some we keep on the wall, and some we keep in the fridge.
> Rick Crosslin: Wait a minute. You have carbon in the freezer here?
Julian Robertson: Yeah, it’s stored cold, because it lasts much longer that way.
> Rick Crosslin: I’ve got to see this.
Julian Robertson: Here are some pieces of carbon.
> Rick Crosslin: In the freezer so it lasts longer. So this must be some expensive stuff.
Julian Robertson: Yeah, these are just a few off-cuts. The expensive rolls are down in the bottom. So this is roll carbon fiber. It’s got some back in here we can remove. So it’s just like a thin flexible mat.
> Rick Crosslin: This side, I can see the fibers
on it, and this side seems sticky though. So how do you activate this on the stickiness on there?
Julian Robertson: So what we do if we’re making a part, we have a mold. This is a typical mold. This is a machined aluminum one. We make them out of different types of material.
> Rick Crosslin: So this is the mold you’re going to make the part on.
Julian Robertson: Yeah. Then we layer. This gets cut to shape, laid in the mold. Then sometimes we get bubbles or something like that.
> Rick Crosslin: Yeah, how do you keep all the air out of it?
Julian Robertson: Then we vacuum bag it.
> Rick Crosslin: So you got a vacuum bag here hooked up to the air. And what are you going to do here?
> We’ve got a valve in there. Part of it’s inside; part of it’s outside with a rubber seal on there. I’ve got seal tape on the ends here of this tube. And it sucks it all down. This part’s already been cured, so it already has the extra resin in there.
> Rick Crosslin: So that makes it a uniform push, a PSI or pressure against it, so your finished product is the way you want it. So when you take that out, is thiswhat you end up with, Julian?
Julian Robertson: Yeah, it goes in an oven to cure, and that’s the finished part which came straight off this mold. You have quite a nice surface finish, because the vacuum bag pushes everything together. It’s really solid.
> Rick Crosslin: That’s amazing science. The technology that goes from carbon fibers, to someone who’s skilled to make this part, to pulling a vacuum on it, to heating it, to the racetrack. That is a lot of cool things going on here.
Julian Robertson: The vacuum is our friend. It’s a pretty powerful thing. If you pull a vacuum, that’s fifteen pounds per square inch, say over that part which is probably 500 square inches, that’s like 7500 pounds pushing down on that part. You wouldn’t be able to do that by putting books on it or anything like that or holding it with your hand.
> Rick Crosslin: Okay Julian, I noticed that that was a small piece, but these are bigger pieces. Do you pull a whole vacuum on these or what is going on here?
Julian Robertson: It depends how big it is. Like this, it would be hard to pull a whole vacuum on it, because it’s so big. But you can pull a vacuum on part of it. This is actually the nose on one of our Grand Am Sports cars. You can see here it’s been damaged during a race. So we’re going to repair it. We’ll grind that out, put some carbon fiber on it, put a local vacuum bag on it there, and then let it cure. Once it’s come out and everything is cured and it’s back to its normal strength, then we’ll repaint it. Things are prepared for paint over there, and then they go into the paint booth and get a paint job.
> Rick Crosslin: The designs of all of these are worked out by engineers.
Julian Robertson: Yeah. We build what we call a solid model of the car on the CAD. CAD is Computer Aided Design. So he can make a full size or an accurate representation of the real car, and when he designs parts, we can check how they fit in with all the other parts by looking at a solid model, as we call it.
> Rick Crosslin: Modeling is a pretty important part of science. You guys take modeling to like the highest degree!