This Fearsome *Titan Games* Event Reveals the Value of Torque

I’m oddly attracted to The Titan Games. I think we can all agree that this is the newest incarnation of the popular ’90s show American Gladiators. It’s not the theatrics that I enjoy, it’s the crazy competitions. As you can imagine, there’s a bunch of cool physics to talk about for some of these events. Actually, if you use a little bit of physics you might be able to get an advantage over your opponent.

In this case, the event is the Herculean Pull. The main idea is to pull some horizontal poles out of a giant wedge. The two contestants are trying to pull the poles out from different sides. There’s a chance you could reach a pole before the other person and win the easy way. But if you’re both pulling on the same pole, you need to use some physics. Here, check out this clip from the show.

The physics trick is to not just pull out on the pole—but also UP! Yes, pull out and up. This is especially true if you are on the losing end as you can see in the example above. She makes the mistake of pulling out and down (because that seems more natural), but it leads to her loss.

Why do you want to pull UP? Let me draw a simple force diagram showing the pole along with the forces acting on this pole.

Rhett Allain

There’s a lot going on in that diagram. Let me break it down for you (that’s what I do). The most obvious forces are the two pulls from the contestants. I have labeled these “A” and “B” to be as generic as possible. In this diagram, both of them are pulling down a little bit. The next set of forces are the “normal forces”—labeled with the “N” for normal. These forces are a result of the pole pushing against the edges of the wedge hole. Since the pole doesn’t go into the wedge material, we know the wedge pushes back on the pole. This is essentially the same force that pushes up on a book sitting on a table. Without this force, the book would just move right through the table—and that would be super weird.

The last pair of forces are the frictional forces (I have labeled them as Ff1 and Ff2). The frictional force can be pretty tricky, but we can still make a fairly simple model for the magnitude of a frictional force. In the case where two objects are sliding against each other, the frictional force depends on the two types of materials interacting and the magnitude of the normal force. As an equation, it would look like this.

Rhett Allain

In this expression the μk is just a coefficient that changes for different interacting materials. Let’s say we have wood rubbing against plastic. The coefficient of friction could be around 0.2 (that’s just an estimate). But it’s not just the coefficient. The frictional force also depends on the normal force. The harder those two surfaces are pushed together, the greater the frictional force.

But where is the physics trick to win this competition? I’m getting there. We need one more physics idea to understand the trick: torque. The idea of torque can get quite complicated, but in some cases it’s not too bad. Take the example of a door. If you want to open the door, you need to exert a torque on it. So, where should you push on the door? On the side with the hinge or on the side opposite the hinge? Yes, you know the answer. If you push on the side with the hinge, the door will not open not matter how hard you push. This is because torque is a product of force and distance from the rotation point.

Maybe this diagram will help.

Rhett Allain

The two forces push with the same magnitude, but the one farther from the hinge has a greater distance and thus a greater torque. There. That is your quick introduction to torque. Now back to that giant pole. Let’s assume for a moment that the pole is at rest and in equilibrium (not moving, not rotating). In this case, two conditions must be true. The total vector force must be equal to zero Newtons (otherwise it would accelerate) and the total torque must be zero (otherwise it would have an angular acceleration). And there have to be both positive and negative torques in order for them to add up to zero. Let’s say that a torque that would make something rotate in the clockwise direction is negative. That will work.

Since the force is really in two dimensions, I get the following three equations for equilibrium.

Rhett Allain

Finally—we are ready to answer the question. Let’s look at the forces on the pole again. In the x-direction, there are four forces. There are the two forces from the humans (or at least a component of the force) and then there are the two frictional forces. Let’s say these all add up to zero. In that case, one person would have to pull much harder than the other person to overcome both the other pull AND the frictional force.

If you can increase the frictional force, you can make it harder for the other person to pull out the pole. This is where the torque on the pole matters. Imagine that both humans are pulling down as you can see in the diagram above. Also, let’s add up the torques as calculated from the right end of the pole (you can pick any point though). The right-pulling person pulls down on the pole and this produces a negative (clockwise) torque. The other two forces that contribute to the total torque are the two normal forces. The normal force on the left pushes up and creates a positive torque and the normal force on the right pushes down with a negative torque. Oh, the left-pulling person produces no torque since the torque distance for that person is zero.

What if there was a way to increase the normal force on the right (labeled N1) in the diagram? With a greater normal force you would also get a greater frictional force. This would make it harder for the left-sided person to pull out the pole. Here, maybe this updated force diagram will help.

Rhett Allain

By pulling UP on the right side, the normal force on that side also has to increase in order to get the total torque to zero. This increase in normal force increases the friction. That’s extra help in preventing the pole from sliding to the right. It might seem natural to pull down, but pulling down just makes it easier to lose. If you have Herculean strength it probably doesn’t matter—but for normal people, it can make the difference between winning and losing.


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This Fearsome *Titan Games* Event Reveals the worthiness of Torque

i am oddly attracted to The Titan Games. I do believe we can all agree that this is actually the latest incarnation regarding the popular ’90s show United states Gladiators. It isn’t the theatrics that I enjoy, oahu is the crazy competitions. Understandably, there’s a couple of cool physics to generally share for some among these events. Really, if you are using some physics you may be able to get an benefit over your opponent.

In this case, the function could be the Herculean Pull. The primary idea should pull some horizontal poles from a huge wedge. Both contestants are trying to pull the poles out of different sides. There is a possibility you could reach a pole ahead of the other person and win the straightforward method. But if you’re both pulling on the same pole, you should utilize some physics. Right here, discover this clip from show.

The physics trick is always to not only pull out on the pole—but additionally UP! Yes, grab or more. This is especially valid if you are regarding losing end as you can see in instance above. She makes the blunder of taking out and down (because that appears more natural), however it results in the woman loss.

How come you need to pull UP? i want to draw an easy force diagram showing the pole combined with forces performing on this pole.

Rhett Allain

There’s a lot happening in that diagram. I’d like to break it down available (that’s the things I do). The obvious forces will be the two pulls through the contestants. I’ve labeled these “A” and “B” to be since generic as you are able to. Within diagram, both of those are pulling straight down a little bit. The next group of forces are the “normal forces”—labeled using the “N” for normal. These forces are a outcome of the pole pressing against the edges regarding the wedge opening. Since the pole doesn’t go in to the wedge product, we all know the wedge pushes back regarding pole. This might be simply the exact same force that pushes through to a book sitting for a dining table. Without this force, the book would simply go through the table—and that might be super strange.

The final set of forces will be the frictional forces (I have labeled them as Ff1 and Ff2). The frictional force are pretty tricky, but we can still produce a fairly simple model for the magnitude of the frictional force. In case in which two objects are sliding against one another, the frictional force depends upon the two types of materials interacting and magnitude regarding the normal force. Being an equation, it could seem like this.

Rhett Allain

Within expression the μk is really a coefficient that changes for various interacting materials. Let’s say we’ve lumber rubbing against synthetic. The coefficient of friction could possibly be around 0.2 (that’s simply an estimate). But it is not just the coefficient. The frictional force also depends on the normal force. The harder those two areas are pushed together, the more the frictional force.

But in which may be the physics trick to win this competition? I am getting there. We are in need of another physics concept to know the secret: torque. The idea of torque will get quite complicated, however in some situations it is not too bad. Just take the example of a door. Should you want to open the doorway, you need to exert a torque on it. So, where in the event you push in the home? On the side with the hinge or on the side opposite the hinge? Yes, you realize the answer. In the event that you push on the side utilizing the hinge, the entranceway will not open maybe not matter just how hard you push. This is because torque is really a product of force and distance from the rotation point.

Maybe this diagram will help.

Rhett Allain

The two forces push with the exact same magnitude, but the one further from the hinge includes a greater distance and therefore a larger torque. There. Which your quick introduction to torque. Now back again to that giant pole. Let’s hypothetically say for a minute that the pole reaches remainder plus in equilibrium (not going, maybe not rotating). In cases like this, two conditions should be true. The total vector force must certanly be equal to zero Newtons (otherwise it would speed up) and the total torque must be zero (otherwise it might have an angular acceleration). And there have to be both negative and positive torques to allow them to total up to zero. Let’s imagine that a torque that will make something turn into the clockwise way is negative. That may work.

Since the force is actually in 2 dimensions, we obtain the after three equations for balance.

Rhett Allain

Finally—we are ready to answer the question. Let’s look at the forces regarding the pole once again. In the x-direction, you will find four forces. You will find both forces from the humans (or about an element regarding the force) and you can find the 2 frictional forces. Let’s say all of these soon add up to zero. If that’s the case, one individual would have to pull a great deal harder than the other individual to overcome the other pull AND the frictional force.

When you can raise the frictional force, you may make it harder for the other person to pull out the pole. That’s where the torque in the pole issues. Imagine that both humans are pulling down as you care able to see in the diagram above. Additionally, let’s mount up the torques as determined from right end regarding the pole (you can pick any point though). The right-pulling individual brings down regarding the pole which creates a bad (clockwise) torque. Another two forces that contribute to the sum total torque will be the two normal forces. The standard force in the left pushes up and produces a positive torque additionally the normal force regarding the right pushes down by having a negative torque. Oh, the left-pulling person creates no torque since the torque distance for see your face is zero.

Let’s say there clearly was ways to increase the normal force in the right (labeled N1) inside diagram? Having a greater normal force you would additionally obtain a greater frictional force. This will ensure it is harder for the left-sided person to grab the pole. Right here, possibly this updated force diagram may help.

Rhett Allain

By pulling through to the right part, the standard force on that part even offers to increase in order to get the sum total torque to zero. This increase in normal force escalates the friction. That’s additional assist in avoiding the pole from sliding towards the right. It may seem normal to pull down, but pulling down simply helps it be more straightforward to lose. If you have Herculean strength it most likely does not matter—but for normal people, it can make the distinction between winning and losing.


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The Physics of the Speeder Chase in ‘Solo: A Star Wars Story’

I make it my job to hunt through all the best trailers and find some cool physics thing to explore. In this case, it’s the trailer for Solo: A Star Wars Story—the Han Solo-led movie, scheduled to come out in May, that takes place some time before Episode IV: A New Hope. Right at the beginning, we see Han driving some type of speeder in a chase scene, taking a super-sharp turn with another speeder in pursuit. Here’s the interesting physics stuff: Notice how it looks like it is sliding around the curve? Why does it do that? Is that how you would actually drive a make-believe speeder?

To answer these questions, we need to think about the nature of forces. Suppose I push on some object at rest such that my push is the only significant force on that object. This could happen with a boat sitting in still water, a hockey puck on ice, or a small spacecraft out in deep space (don’t worry about how that object got into space). What does the object do? A common answer will be to say that the object moves. That’s not wrong, but “move” is not the best answer. With a constant a force, an object increases in speed—that is to say, it accelerates. Acceleration is a measure of the change in velocity of an object, so we could also say that a force changes an object’s velocity. That’s key.

There’s one more really important idea to understand—velocity is a vector. A vector is a quantity in which the direction matters (other vectors are: force, gravitational field, position). If a quantity doesn’t depend on direction, we call that a scalar (like time or mass or electric charge). Since forces change velocity and velocity depends on direction, this means that it takes a force to change the direction of a velocity. Or you could say it takes a force to turn Han Solo’s speeder.

How about a demonstration to show you how this works? Suppose I take a bowling ball and roll it along the floor (everyone should have a bowling ball handy for physics demos). This ball will essentially act like an object moving with a constant velocity since the frictional force is small. I want to make this ball change directions by hitting it with a stick. Which way should I hit it? Watch this.

Just to be clear, let me include this diagram showing the velocity of the ball and the direction of the force.

This sideways tap makes the ball change direction of its motion, but it doesn’t really change how fast it rolls. So really, you can break forces into two components. Forces in the same direction (or opposite) direction as the velocity either make it speed up or slow down. Forces that are perpendicular to the motion (sideways forces) make the object change direction. But you already knew that: When you swing a ball around on a string, it mostly moves at a constant speed but the sideways force from the string causes it to change direction and move in a circle.

Now back to Han Solo’s speeder. I’m not sure exactly how this vehicle drives, but I can make some assumptions (and you can’t stop me). First, it seems likely that those thrusters in the back of the speeder exert some type of force on it. Second, there has to be some significant frictional force pushing in the opposite direction of the speeder’s motion. f not, the thrust from the engines would just make that thing keep speeding up until it got to ludicrous speeds. My last assumption is that the speeder has to use these same rear thrusters for changing direction—unlike an Earth-bound automobile, which uses friction between the tires and the road to make a turn.

How about a breakdown of this slide turn from the trailer? I can’t really do a proper video analysis because of the camera angle, so instead I will just talk about it conceptually. Let me break down the motion into three moments as seen in the diagram below.

At position 1, the speeder is still moving to the left—but Han has turned the speeder so that the thrust can start to push perpendicular to the motion of the vehicle. Next at position 2 the speeder is in the middle of the turn. You can see that the thrust is making it turn. But you can also see that the vehicle thrust is pushing in a way that only changes the direction of the vehicle and not its speed. Finally, at position 3, the turn is complete. Han just needs to turn the speeder so that the thrust is in the same direction as the motion (I assume to counteract the frictional force).

If you don’t like thinking about moving in circles, you have another option. How about this? In position 2 (above) notice that the speeder thrust is to the left and up. The left-pushing part of this thrust is in the opposite direction as the motion of the vehicle, so that it makes it reduce its right-moving speed. The up-pushing part speeds up the vehicle in the upward direction. In the end, this whole maneuver has to do two things: stop the vehicle moving to the right and speed up the vehicle moving upward (in the diagram). That’s why the thrust has to angle the way it does.

Homework: Yes, I do have one question for you to work on. Suppose this speeder is about the size and shape of a terrestrial car. In that case, you can estimate the thrust force needed to move it along at a constant velocity. Now that same force has to make make the car turn—but the turning force depends on the mass of the car (unlike driving forward which only depends on the shape). Use this to estimate the thrust to mass ratio for the speeder. Yes, I think this can be done. You might need to make some rough estimates of vehicle speed and turning radius.

Can an Airplane remove for a going Runway?

This real question is probably as old because the airplane itself. It goes something such as this:

An airplane includes a takeoff speed of 100 mph (I just made that number up). What if it gets for a super giant treadmill machine that moves backwards at 100 mph. Could a plane with this giant treadmill machine remove or would it not simply sit there going at 0 miles per hour?

Initial question a reasonable individual would ask is “in which would you get yourself a giant plane-sized treadmill machine that goes 100 miles per hour?” Yes, which indeed a great question—but i will not answer it. Instead, i will offer this question top physics answer I am able to.

Before i actually do that, i ought to explain that others also have answered this question (not surprising as it’s super old anyway). First, there was the MythBusters episode from 2008. In fact, they didn’t answer the question—they did issue. The MythBusters made a giant conveyer belt having plane about it. It had been awesome. Next, there is the xkcd response to this concern (additionally from 2008).

Now you get my answer. I shall respond to with different examples.

A Car on a Conveyer Belt

This isn’t so difficult. Let’s say I put an automobile going 100 mph on a conveyer gear that is also going 100 mph? It could appear to be this (something like this):

Actually, there’s probably no real surprise right here. The vehicle’s tires would roll at 100 miles per hour as the treadmill machine (or conveyer gear) moves back at 100 mph so that the vehicle stays stationary. Really, here is a somewhat cooler example (with the same physics).

Let me reveal an test (also from MythBusters) which they shot a ball at 60 mph out of the back of a truck additionally going 60 miles per hour. You can view your ball stays fixed (with regards to the ground).

Super Brief Takeoff

Here is a airplane from Alaska that takes off in a really short distance.

How exactly does this work? We’ll provide you with a hint—there is definitely a strong wind blowing in to the front side for the plane. Without a headwind, this couldn’t happen. However if you consider it, this brief lose is certainly much such as the vehicle regarding treadmill machine. For the plane, it generally does not drive on the floor, it “drives” in the air. In the event that airplane possesses takeoff rate of 40 miles per hour and is in a 40 mph headwind, it doesn’t even have to go at all according to the ground.

Airplane for a Conveyer Belt

Now let us do it. This is a short clip from MythBusters launching a plane on a going treadmill machine.

Yes, it requires off. A plane takes faraway from a runway relocating the opposite direction? But why? It is because the tires for a plane never really do anything. The only function for the wheels would be to produce low friction between your aircraft together with ground. They do not also push the airplane forward—that is performed by the propeller. Truly the only distinction whenever releasing an airplane for a moving runway is the fact that wheels will spin at twice the standard speed—but that willn’t matter.

Therefore the airplane on a treadmill works, but how about a case where in fact the plane wouldn’t take off? Imagine if the plane ended up being similar to a glider with motorized tires? For a normal runway, these motorized tires would raise the rate for the glider until it reached takeoff speed. However, if you place this on a going runway, the tires would spin on right rate and cancel the motion regarding the treadmill so the airplane would remain motionless and not reach the proper rate for the launch.

okay, making sure that is the response to everybody’s favorite question. But never worry, this answer wont stop the endless discussion—that will go on forever.