speed is cool and all but have you ever heard of
✨ acceleration ✨
this post was submitted on 11 May 2024
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Constantly
Yes. This is when you are really good at making your food last longer.
You're thinking of refrigeration.
Acceleration is when matter in space starts to coalesce into stellar objects.
You're thinking of accretion. I don't know what acceleration means, though
It's when you pop a minty gum in your mouth and chew it. You've accelerated your breath.
You're thinking of exceleration. I don't know what acceleration means, though
No that’s when you put everything in a spreadsheet. You’re thinking of inceleration.
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1.) 0.28 g 2.) 15.7 g 3.) 0.0034 g
I assumed 1m radius for the first and 5m for the second, particularly the second sounds off. Anyway... The centripetal force from Earth's rotation is quiet negligible compared to its gravitation.
5 meters is definitely way too short for the chair swing ride. Look at the people in the seats. It's definitely at least 10 meters.
Assuming 10 meters and 100 km/h, that gives about 7.9 g. That's in the range of what fighter pilots might experience and well beyond where most people black out, so that's still definitely too high.
Looking it up online, this is a pretty classic physics problem and the numbers you might see around it are closer to a radius of 12 meters and a speed of 13 to 17 m/s. Taking that as 15 m/s (54 km/h), that works out to about 1.9 g, which I can subjectively say feels much closer to the real value if you ever ride on one of these.
So, the second one is about 1.9 g
Yeah, those rides complete a rotation in ~10 seconds given what I was able to count in a couple YouTube videos, so 36°/sec. If they have a 10m radius, the linear velocity would be 6.283 m/s or 22.62km/he.
The 100 km/h seems a bit much to me, too, but I'm having a hard time finding info on the speed of these...
Looked up a video of a gentle one. A revolution takes about 2𝜋 seconds, at which the speed in m/s is the same as the radius in meters, or around 5. Multiply by 3.6 to convert into 18 km/h, which seems realistic for the milder ones. The apparent horizontal centrifugal acceleration will then be 𝑣²/𝑟 = 5 ms⁻² ≈ 0.5𝑔, which corresponds to an angle of approx. 26° from the verical, reasonably close to the video.
The one depicted in the image probably goes about 2x as fast, pulling perhaps 2𝑔 horizontally for an angle of approx. 63°.
How does one count in π • seconds?
It's about 6.5 seconds in the video. I rounded that to 2𝜋 so I could do the math in my head (other than the tan⁻¹(0.5), of course)
"One, two, thr- pi"
Considering most people will start to lose consciousness and risk heart issues at like 5g, I’m pretty sure the speed is way off on number 2.
Thus neatly making the case that radius matters.
Girth, you say?
One is but a two pi greater version of the other.
I once lived with a sort of science ~~skepticist~~denier (didn't believe in the moonlanding nor did he believe that the earth wasn't flat). He was of the belief that scientists are deceiving the public and one of the examples he gave was that they claim that the earth rotates at 1 670 km/h but if we look outside that's very clearly not the case and if jump we aren't flung at that speed to the side. I spent half an hour in a back and forth trying to explain the concept of relative velocity and inertia. It didn't go anywhere.
Edit: changed to denier based on the comment by logos.
Ask them to jump inside a train
Not to be pedantic but I would call them more of a science denier than a skeptic. It's too close to scientific skepticism which is completely different.
My aunt once mentioned that if the earth wasn't rotating that we'd all be crushed by gravity, and it's only the spinning cancelling out that force. I responded by pointing out that gravity is also present at the poles, where you can casually walk faster than the rotation of the earth, and yet no one has been crushed to death there. She responded that it must be something to do with the magnetic fields, and wouldn't listen to anything I said when I tried to explain the basic concept of angular velocity.
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Have him drop a tennis ball in a moving vehicle. It won't make him understand but you can at least say you tried.
Earth is merely spinning at 15 degrees per hour.
So one turn takes about... 24h?
Nobel prize coming your way
Oh my god.
Yes, that's how the day and night cycle works
I feel like this is the most concise answer in this thread.
Omega squared baby!
acceleration is the answer
Yes, and a = v^2/r.
Merry-go-round: small radius, big acceleration!
Earth: big radius, small acceleration.
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It's almost like there's no such thing as absolute velocity or something
Relativity
If you were only going 6 km/h you were doing it wrong
So what would happen if Earth suddenly stopped spinning? Would every building, tree and mountain suddenly fall Eastward?
I believe we'd have worse problems since the atmosphere would still be moving.
Yes, the Earth would be completely spherical in a matter of seconds.
Rather than speed we use radians/degrees per second. One of these things is very small.
short advantage
Circumference.
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