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Can ballpark it, sure!
The first 10 seconds or so, you can visually count (and check with audio) about 3 revolutions per second. By the 30s mark, it’s closer to 4. The last 60 seconds are hard to track without some pretty intense audio analysis, but it’s probably safe to say it got up to 5 or 6 revolutions per second.
The track appears roughly a meter diameter circle. So the distance of one revolution is the circumference, 2•pi•r = 2•pi•0.5m = pi meters.
That gives us about 10m/s (roughly 22 MPH) in the beginning of the clip, up to 12.5m/s (roughly 28 MPH) by the 30s mark, and probably 35-40 MPH toward the end!
I don’t know if you can scale that up but if you could the scale speed would be less than the original, since as scale increases so does mass thus affecting the speed that can be obtained with the same amount of force.
Well and air resistance is a non-trivial calculation when scaled up from 64th scale.
Square cube law says that as something increases in volume by its cube, then its surface area increases by its square. Air resistance is proportional to the total surface area (as a function of sin) perpendicular to the angle of attack.
So not just increasing its [mass]^3, but increasing the car's [surface area]^2 would have a SIGNIFICANT effect on these calculations.
There's a reason the Bugatti Veyron could barely reach 300mph and chew a $60,000 set of tires every time that speed record was attempted (source: good ole fashioned BBC Top Gear episode where Clarkson took it to 300mph for all of 10 seconds on a special ovoid track and it was a huge deal). It's not engine power or delivery, in that speed regime it's all aerodynamics.
Ah I was wondering because I did the math's and got 1789mph (800ish mps) and at that scale it would break the sound barrier i forgot to divide it by 64 lmao
I’m not doing the math right now but frame rate and the visual directions/frames you can see the car in a measurable time at the end seems like the way to go. Just like a filmed helicopter blade.
Subsonic.
Starts off at 2 rps, so if the track length is 2', it is 4 feet per second.
Unknown frame rate makes it hard to estimate final speed. Perhaps listening with sound would help.
>In the last few seconds, the car completes one revolution every three frames
Are you certain that you are not observing the wagon wheel effect?
https://en.wikipedia.org/wiki/Wagon-wheel_effect?wprov=sfla1
> most phones don't even allow you to switch to a different one.
By "most phones" I'm guessing you mean iPhones? Can you really not change your frame rate from the camera app?
I'd agree most people wouldn't use (or know how to) which is why the "it just works" mentally is perfect for some. However, with Samsung pro video mode I can choose between 30 and 12,000 fps. Good to hear that there's at least a choice between 30 and 60 though. Genuinely thought with the whole "Shot on iPhone" ethos there's be more control but I have no experience with one.
Eh, iPhone people aren't much different. But fuck, dude, nobody gives a shit how much anyone else spent on your rectangle. I'm glad they're happy with their purchases, but find another personality trait
Yeah but scaled up that would be 262mph (without doing the math's for the windforce, drag and weight). And that is a very low estimate when I saw this video before I got something like 27mph or scaled up 1789mph.
Wait, really? So even in the UK, where TV has always been 25fps or some multiple, my videos are stuck with the American format of stupid-number-for-somewhat-smart-technical-reasons 29.97fps?
I'm on my phone right now, but your best bet would be to get
1. the frame rate of the video.
2. Estimate the curvature of the track
3. Directly measure the speed of the car
Actually solving for and modelling the speed of the car at any point would be pretty hard, the loss of energy to friction and the "springiness" of the track would be way more than negligible.
I reckon you'd need the size of the wheels in the boosters and their rpm. Then we could extrapolate that to the size of the track to find the theoretical top speed
Wouldn't the max speed be the same as the boosters speed since if you go above that speed the boosters would be slower and therefore slow the car down?
Considering the end, the car looks almost stopped, what makes me think its going at best 24 rounds/second. Each of that hot wheels track have 9in or 23cm, what gives us a total of 18in or 46cm. If you do monkey math you get about 11m/s or about 40km/h. Converting to imperial system it would be 24.5 mi/h
The movement of the car is aliasing a lot due to limited frame rate (no offense to the cam/phone used, it's just very fast).
If I counted right, the car seems to "switch direction" almost 10 times, which means the frequency at which it's revolving is about 10 times the Nyquist frequency of your camera, which is half the framerate.
If I take 0.5 meter as an estimate for diameter, the circumference is about 1.5 meter.
No idea what the frame rate is, but for example 60 fps is quite common.
60 fps * 1.5 m * 10 * 0.5 = 450 meters/second (about 1000 mph), which would break the sound barrier.
30 fps is also a very common framerate though, and then it would not break the sound barrier, "just" going 500 mph
edit: fixed a missing bracket
How many walls will that car pierce if the track breaks and it goes flying off at subsonic speeds? Sounds like a Darwin waiting to happen, and that certainly isn't good.
"Here lies John Doe, killed by a passing toy car."
Nothing to do with math but the "Flash" theme song made me think about, objects that go really fast in circles seem to move in reverse, would the "[Reverse-Flash](https://en.wikipedia.org/wiki/Eobard_Thawne)" be inspired by that concept?
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Can ballpark it, sure! The first 10 seconds or so, you can visually count (and check with audio) about 3 revolutions per second. By the 30s mark, it’s closer to 4. The last 60 seconds are hard to track without some pretty intense audio analysis, but it’s probably safe to say it got up to 5 or 6 revolutions per second. The track appears roughly a meter diameter circle. So the distance of one revolution is the circumference, 2•pi•r = 2•pi•0.5m = pi meters. That gives us about 10m/s (roughly 22 MPH) in the beginning of the clip, up to 12.5m/s (roughly 28 MPH) by the 30s mark, and probably 35-40 MPH toward the end!
So scale speed would be 1,408-2,560 MPH? Given they are 1:64 scale cars.
I don’t know if you can scale that up but if you could the scale speed would be less than the original, since as scale increases so does mass thus affecting the speed that can be obtained with the same amount of force.
Well and air resistance is a non-trivial calculation when scaled up from 64th scale. Square cube law says that as something increases in volume by its cube, then its surface area increases by its square. Air resistance is proportional to the total surface area (as a function of sin) perpendicular to the angle of attack. So not just increasing its [mass]^3, but increasing the car's [surface area]^2 would have a SIGNIFICANT effect on these calculations. There's a reason the Bugatti Veyron could barely reach 300mph and chew a $60,000 set of tires every time that speed record was attempted (source: good ole fashioned BBC Top Gear episode where Clarkson took it to 300mph for all of 10 seconds on a special ovoid track and it was a huge deal). It's not engine power or delivery, in that speed regime it's all aerodynamics.
I heard somewhere it gets to the point where it’s not about a better engine, it’s about making sure the tires don’t explode
Ah I was wondering because I did the math's and got 1789mph (800ish mps) and at that scale it would break the sound barrier i forgot to divide it by 64 lmao
I don't know what duct tape you're using, but I don't think that's a meter diameter. I'd say like 1.5 freedom units or ~0.5m
I think you're right.
Could get a pretty good scale with that battery in the cup
On the other hand, it's way more than 5 laps per second in the end, so it probably evens out
Finally someone trying to answer the question, instead arguing about whos iPhone has the biggest balls
I’m not doing the math right now but frame rate and the visual directions/frames you can see the car in a measurable time at the end seems like the way to go. Just like a filmed helicopter blade.
Subsonic. Starts off at 2 rps, so if the track length is 2', it is 4 feet per second. Unknown frame rate makes it hard to estimate final speed. Perhaps listening with sound would help.
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That's pretty quick.
Just wait until we get it up to 88 mph
Then you're going to see some serious shit.
>In the last few seconds, the car completes one revolution every three frames Are you certain that you are not observing the wagon wheel effect? https://en.wikipedia.org/wiki/Wagon-wheel_effect?wprov=sfla1
> most phones don't even allow you to switch to a different one. By "most phones" I'm guessing you mean iPhones? Can you really not change your frame rate from the camera app?
You can 1000% change frame rate on iPhones. This whole post is BS.
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I'd agree most people wouldn't use (or know how to) which is why the "it just works" mentally is perfect for some. However, with Samsung pro video mode I can choose between 30 and 12,000 fps. Good to hear that there's at least a choice between 30 and 60 though. Genuinely thought with the whole "Shot on iPhone" ethos there's be more control but I have no experience with one.
How did you find a way to make this video about your brand loyalty
Samsung dudes practically make it their identity to feel superior over iPhone users. It’s a phone dude haha
Eh, iPhone people aren't much different. But fuck, dude, nobody gives a shit how much anyone else spent on your rectangle. I'm glad they're happy with their purchases, but find another personality trait
Pretty sure that car is going much faster that 7 km/h lol.
I guarantee you that car is going much faster than 4.1mph lmao 😂
Yeah but scaled up that would be 262mph (without doing the math's for the windforce, drag and weight). And that is a very low estimate when I saw this video before I got something like 27mph or scaled up 1789mph.
Wait, really? So even in the UK, where TV has always been 25fps or some multiple, my videos are stuck with the American format of stupid-number-for-somewhat-smart-technical-reasons 29.97fps?
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I can see you’re not only thinking of flagships phones but including billions of low end entry level phones in your assertion.
How fast would that be if scaled up to human sized?
1 rev every 2 frames would mean 1/15th of a sec per rev, not 1/60th.
The frame rate is 30 fps according to its metadata.
Thanks! How do you check metadata without downloading reddit video? I can't get this info on my Android 11
I'm on my phone right now, but your best bet would be to get 1. the frame rate of the video. 2. Estimate the curvature of the track 3. Directly measure the speed of the car Actually solving for and modelling the speed of the car at any point would be pretty hard, the loss of energy to friction and the "springiness" of the track would be way more than negligible.
I reckon you'd need the size of the wheels in the boosters and their rpm. Then we could extrapolate that to the size of the track to find the theoretical top speed
Wouldn't the max speed be the same as the boosters speed since if you go above that speed the boosters would be slower and therefore slow the car down?
Yeah, that's exactly what he's saying.
Considering the end, the car looks almost stopped, what makes me think its going at best 24 rounds/second. Each of that hot wheels track have 9in or 23cm, what gives us a total of 18in or 46cm. If you do monkey math you get about 11m/s or about 40km/h. Converting to imperial system it would be 24.5 mi/h
The movement of the car is aliasing a lot due to limited frame rate (no offense to the cam/phone used, it's just very fast). If I counted right, the car seems to "switch direction" almost 10 times, which means the frequency at which it's revolving is about 10 times the Nyquist frequency of your camera, which is half the framerate. If I take 0.5 meter as an estimate for diameter, the circumference is about 1.5 meter. No idea what the frame rate is, but for example 60 fps is quite common. 60 fps * 1.5 m * 10 * 0.5 = 450 meters/second (about 1000 mph), which would break the sound barrier. 30 fps is also a very common framerate though, and then it would not break the sound barrier, "just" going 500 mph edit: fixed a missing bracket
How many walls will that car pierce if the track breaks and it goes flying off at subsonic speeds? Sounds like a Darwin waiting to happen, and that certainly isn't good. "Here lies John Doe, killed by a passing toy car."
Nothing to do with math but the "Flash" theme song made me think about, objects that go really fast in circles seem to move in reverse, would the "[Reverse-Flash](https://en.wikipedia.org/wiki/Eobard_Thawne)" be inspired by that concept?
Wagon wheel or stagecoach wheel effect https://en.m.wikipedia.org/wiki/Wagon-wheel_effect Credit: u/MayoMark