That’s true, Mike, I do seem to remember that.
Meanjoe, that’s also true. It was relativity illustrated. Hey, that would be a great name for a physics magazine… 
Oh that age old question again. If you jumped up in the air, should you land a few feet away as the earth rotates?
yeah if the support structure under the cover was uneven it would flip like tiddlywink if run over just right, especially if one car made it wobble and the next car hit it on the edge a bit.
you would be amazed at how far a couple hundred pounds of steel will fly when three tons of steel are dropped on it just right…
oh shoot, I commented after the first page. I didn t realize that there were six more…
Oh that age old question again. If you jumped up in the air, should you land a few feet away as the earth rotates?
Whether it is you or a manhole cover Your inertia, kinetic energy or angular momentum whatever you prefer you would not land a few feer away imho
Basketball would sure be interesting…
Fact is, you’re traveling at the same speed as the earth turning under you, and the air around you does too. With nothing to oppose your body traveling at the same speed as the earth and the air around you, there’s no relative speed.
Now the interesting effect would be if there were no gravity… there’d be no centripetal force and you’d fly off the surface into space… but your speed would stay the same. The earth at the equator moves at about 1,000 mph. However, according to Scientific American, the earth (and you) are flying around the sun at about 67,000 mph. And our solar system orbits the galaxy at an estimated 490,000 mph. No telling how fast eth galaxy is moving. So how fast would you actually be going? In truth, how fast you… or the Jennerhole cover… or the car… was moving is entirely relative. Which makes all of the above answers correct.
Cool, huh?
The only speed that matters is the one of the Jennerhole cover relative to the car. Or the car relative to the Jennerhole cover. Depending on how you look at it. It doesn’t matter. The tragedy is no less great.
Yeah I know, gravity. Its the same type of question discussed as kids along with do you get wetter riding your bike faster or slower in the rain.
Mythbusters is often wrong. In regards to the bit about a bullet entering a scope and killing another sniper not being possible I would suggest that someone read Charles Thompon’s Silent Warrior about legendary Marine sniper Carlos Hathcock who did indeed take out a famed North Vietnamese sniper by putting a round through his scope.
This is where the part about the German sniper being taken out by Private Jackson in the Saving Private Ryan movie came from.
Mythbusters is also dead wrong (and then some) with that hokum bit they did about the tornado proof armored car that was impervious to tornados. This was based on the bit about the jet blast from a 747 not overturning it at full bore.
Note the vehicle was sitting back a ways and facing nose on to the jet blast. It doesn’t work that way in tornados. What they should have done is drive by the blast sideways and up close. That thing would go rolling then…
That armored (Ha…) car has been a PR stunt for an OK City tv station who call it “The Dominator”.
What a joke. It’s a Tahoe fitted with funky body panels and in a real tornado that Tahoe would be crushed like a beer can and everyone in it dead on the spot.
I have no idea where “The Dominator” is right now but did see it a couple of years ago on the west side of OK City at the back of a small used car lot on I-40 and MacArthur. Surely not…
Well…jumping up, you can discount the Earth’s rotation…and I even did so in my “bullet” analogy…but once you get into rockets, or even artillery, you have to account for Coriolis Effect.
Anything travelling in circular motion is under acceleration, and that all stops once you “break the surly bonds” and that. You come back down onto a world that’s “shifted” in your absence…and land somewhere other than where the map says.
In my example, I assumed the bullet is in flight such a short time that the target doesn’t rotate a significant amount, and thus approximates “straight line” motion. This is like not accounting for Earth’s curvature when leveling construction: technically incorrect, but won’t make a bit of difference IRL. (Though I hear NASA has a special “flat floor” that is precise enough to take Earth’s curvature into account…)
Well, I suggest that at 10am central time Sunday we all face south and take a good leap to the south. maybe we can give the earth just a little shove, so spring comes a little earlier.
Careful on landing…it may be icy.
Yosemite
I’ve watched Mythbusters a few times when they first came on, and they’re just hucksters. It’s okay I suppose for people that like seeing things blown up, the same crowd that watched “The A-Team”, but it isn’t real science anymore than “The A-Team” was a real group of AWOL Vietnam vets.
You sound like a lawyer for the piece of tile…
As long as you brought it up, I was addressing this comment:
The mass of the Styrofoam piece that broke off had very little Mass...but it did have a lot of acceleration.
Since the tile was originally ahead of the wing in the flight path of the shuttle, do you think the tile having “a lot of acceleration” caused the damage?
No, it was due to what I posted earlier-
Like you pointed out, low mass, high speed differential...
BTW- if you run into the back of someone’s car, I’d like to be the fly on the wall when you argue to the judge about why it matters which perspective we have on the collision…I didn’t run into them, they…
^Are you addressing somebody in particular, TT?
Could the shuttle have reentered at a different attitude and not been destroyed?
Could the damaged tile have been patched enough to prevent catastrophic destruction?
@meanjoe75fan sorry you are picking on one of my pet peeves, Coriolis effect. I believe the effect as applied to hurricaines and cyclones is due to the greater speed of the earth at the equator vs the poles causing the spin via basic friction.
As far as missiles go the rotation of the earth from the time of launch till landing, due to the tilt in the earth axis causes the effect.
The earth rotates from west to east, fire a missile say from New york city to milan, from space the missile travels in a straight line, but observation is the missile lands far west of Milan, that is due to the fact between the time of the missile firing and landing, Milan is no longer where it used to be due to the rotation of the earth so it lands in a spot that can be calculated but appears to an earth observer to be a curved path, criminee I shoot at Milan and hit gibralter!!
, as in WW2 calculators for missile distance length and speed seen in Science surplus, wish I had bought one!
@Robert Gift: The really messed up thing is that NASA at least suspected there was something amiss with the tiles–and elected to say nothing to the crew, on the basis of “if you’re doomed anyways, better off not knowing it.”
Now, I know at the time there was no means of scrambling a rescue mission before life support ran out…but couldn’t an unmanned rocket be sent to rendezvous, with oxygen, food, water, and a sack of refractory cement? I have some real big problems with NASA leadership, all the way back. The only reason (IMO) that the moon program had as little loss of life as it had, was due to the stubborn insistence of Werner VonBraun, to put lives ahead of maximizing dV. To give an instance, Saturn V could have saved money, and gained dV, with solid rocket boosters, but they were nixed on flight safety grounds. (And yes, I’m fully aware of the irony of a former SS officer being the ethical anchor of an organization…but, facts are facts.)
I believe the effect as applied to hurricaines and cyclones is due to the greater speed of the earth at the equator vs the poles causing the spin via basic friction.Well, you're closer than most. The effect (W/R/T weather) is due to the LACK of friction, or interaction, between air masses and the ground. If there was enough friction, the air would do what the ground was doing. Near ground level, air tends to flow from high pressure to low; at altitude, it's more clockwise around the high pressure system. If you put a greased pig on a *perfectly* frictionless floor, said pig should spin one revolution per day, clockwise.
@TwinTurbo: Okay, fair’s fair. I gave you ample opportunity to disavow that your trenchant comments were aimed at me. Time’s up, so here you go:
You sound like a lawyer for the piece of tile...I sound NOTHING like any lawyer. Laywers don't know physics from the nether reaches of their own anatomy; they actually think a pound is a unit of MASS similar to a kilogram...and that a "slug" is something on the menu of a French restaurant that you "stay away from if you're smart."
But, hey, nice attempt at a deflection! I guess if I just got schooled in physics as thoroughly as you did, I’d be looking to change the subject, too.
Since the tile was originally ahead of the wing in the flight path of the shuttle, do you think the tile having "a lot of acceleration" caused the damage?There, there...it was the RELATIVE VELOCITY DIFFERENTIAL between the two objects that did the damage--energy imparted in a collision is proportional to mass, times the square of velocity. As a exponential, a big velocity can more than make up for miniscule weight. Acceleration is "how they happened to wind up with such a big differential in the first place," and this historical data is irrelevant to the posed question. Elementary, my dear Turbo.
The reason wind tunnels work (stationary wing and moving air) is that IT MAKES NO DIFFERENCE which part is “in motion”; that’s also why the FAA has a cannon that shoots dead chickens at jet engines: the physics works the same, no matter what part is “in motion,” if the relative velocity matches.
But hey, maybe you simply aren’t obviously wrong; perhaps you’ve stumbled on a whole new understanding of physics, where there IS absolute rest*, and velocities aren’t relative to a reference plane. You can call it “Twin Turbo’s Lack of Relativity Theory,” and you can start with the “Special LORT” (involving solely foam insulation and insulative tiles), and hopefully expand it to a “General LORT” (involving anything crashing into anything else.)
TL;DR: you were somewhat foolhardy to try and best me at physics. Recently, a forum member threw down a gauntlet of sorts, (wrongly) assuming that I had no knowledge of certain aeromedical phenomena associated with the varied forms of hypoxia. Said unnamed member found out, the hard way, that he’d underestimated me. (Though I’m still waiting on my prize–I was told there’d be a prize!) Seeing that, and rushing in anyways, calls your wisdom into question.
*(Yes, I know I’m butchering the concept of “absolute rest,” but I needed a way to describe “zero velocity” differently from, say "zero velocity (relative to Earth), and words failed me.)
FROM:
https://en.wikipedia.org/wiki/Rest_(physics)
In reality, there is nothing at absolute rest. For example, Earth's gravitation constantly pulls objects toward its surface, while Earth is one of the objects the Sun constantly pulls towards itself, causing it to orbit the Sun; the Sun, in turn, orbits the center of the Milky Way; and so on.
A possible contributing factor: The foam composition was changed:
Pull-quote:
The composition of the foam insulation had been changed in 1997 to exclude the use of freon, a chemical that is suspected to cause ozone depletion; while NASA was exempted from legislation phasing out CFCs, the agency chose to change the foam nonetheless.
What happened to the mysteriously flying manhole cover? I almost forgot another “bolt from the blue” incident. A few years ago a nearly round 6ft+ boulder (how much does that weigh? A lot!) fell off a cliff and landed in the middle of a local road. I searched for the article and photo with no success and have to rely on my faulty memory. There was a photo of a County Sheriff’s Deputy standing by the rock with his hand raised touching it. His hand was well below the top. Fortunately it did not squish a vehicle. The only fatality was the road which required 100ft of it being totally replaced. I don’t quite remember how the rock was removed. It could have possibly been rolled by a D-9 Cat off the other side of the road into the river but I’m sure Northern Pacific railroad would have frowned on it smashing their tracks on the way. I think they ended up drilling and dynamiting it in to more manageable pieces and trucking it away. I can understand a rock falling off a cliff. Gravity working as advertised. I still can’t understand a 150-200lb iron manhole cover being ran over by an SUV and leaping 3-4ft up. Gravity somehow being defeated.