The falling elevator and the lost coin...
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The falling elevator and the lost coin...
I suppose to be at the top level of the Empire State building and entering in the elevator for a way back downward.
I suppose also I have a coin held between my fingers.
The doors are closed and the ride starts, but unfortunately just at this moment the cable (retaining the elevator) is broken.
Obviously the elevator (now free) falls, me too (within).
The question is:
if I open my fingers, will the coin fall on the elevator's floor?
There are several answers in the poll above.
1. The coin falls on the floor
2. The coin remains in my hand
3. The coin will be sticked on the elevator's roof
4. The coin will float inside the elevator (like in the space shuttle)
5. I don't know but for sure, after the arrival in the basement it will be difficult to find the coin
I suppose also I have a coin held between my fingers.
The doors are closed and the ride starts, but unfortunately just at this moment the cable (retaining the elevator) is broken.
Obviously the elevator (now free) falls, me too (within).
The question is:
if I open my fingers, will the coin fall on the elevator's floor?
There are several answers in the poll above.
1. The coin falls on the floor
2. The coin remains in my hand
3. The coin will be sticked on the elevator's roof
4. The coin will float inside the elevator (like in the space shuttle)
5. I don't know but for sure, after the arrival in the basement it will be difficult to find the coin
I cannot imagine why nobody though on this before, including myself? It is so simple!...
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re: The falling elevator and the lost coin...
This important (and serious) question is in relation with the torque applied to the wheel.
As explained before, my personal explanation of the gravity is:
1. There is no gravitic field at all (and therefore no force directed to the center of the earth)
2. We are permanently in expansion (the expansion universe since the big bang) and everything around us at the same speed (the reason why we cannot see this expansion)
3. The eventual meters are in expansion also, and any measurement with them is impossible.
4. When I hold a coin in my finger, I oblige the coin to be linked with our expansion speed.
5. When I open my fingers the coin is fried and it's expansion speed decreases (like the square of the time).
The coin don't fall, but the floor encounter and catches it (still in expansion with the main speed)
6. Arriving in contact with the carpet the coin is re-accelerated at the main expansion speed, and applies a force on the floor at this moment (with the restitution of its accumulated energy)
This very controversial explanation can open an important domain of investigation for the gravity wheel.
Suppose a weight attached by a rope to the inner rim of the wheel.
The weight is locked in a compartment very near of the rope attachment point, and climbs from 6:00 to 10:30 (the wheel rotating clockwise).
When arrived at 10:30 the weight is ejected from its refuge and falls (with a real free fall).
The rope is inactive, there is no action (no torque) anymore on the left side of the wheel (creating a temporary unbalance)
SCENARIO n°1:
The weight falls enough down for allowing the extended length of the rope to stop the weight.
At this moment there is a shock in the vertical rope, transmitting all accumulated energy to the inner rim of the wheel (may be at 11:30 this time)
SCENARIO n°2:
The weight falls down (the rope being still inactive), but is stopped somewhere in an intermediate platform (may be at 9:00 of an half sized wheel inside the big one).
Then the smaller wheel drives the weight until 12:00, leaving it at a distance equal to the length of the rope (by the way retrieving its purpose at the right side of the inner rim).
In that case the energy is lost (if the smaller wheel is grounded per example) but the unbalance has not been solved (in contradiction with the principle of conservation)
As explained before, my personal explanation of the gravity is:
1. There is no gravitic field at all (and therefore no force directed to the center of the earth)
2. We are permanently in expansion (the expansion universe since the big bang) and everything around us at the same speed (the reason why we cannot see this expansion)
3. The eventual meters are in expansion also, and any measurement with them is impossible.
4. When I hold a coin in my finger, I oblige the coin to be linked with our expansion speed.
5. When I open my fingers the coin is fried and it's expansion speed decreases (like the square of the time).
The coin don't fall, but the floor encounter and catches it (still in expansion with the main speed)
6. Arriving in contact with the carpet the coin is re-accelerated at the main expansion speed, and applies a force on the floor at this moment (with the restitution of its accumulated energy)
This very controversial explanation can open an important domain of investigation for the gravity wheel.
Suppose a weight attached by a rope to the inner rim of the wheel.
The weight is locked in a compartment very near of the rope attachment point, and climbs from 6:00 to 10:30 (the wheel rotating clockwise).
When arrived at 10:30 the weight is ejected from its refuge and falls (with a real free fall).
The rope is inactive, there is no action (no torque) anymore on the left side of the wheel (creating a temporary unbalance)
SCENARIO n°1:
The weight falls enough down for allowing the extended length of the rope to stop the weight.
At this moment there is a shock in the vertical rope, transmitting all accumulated energy to the inner rim of the wheel (may be at 11:30 this time)
SCENARIO n°2:
The weight falls down (the rope being still inactive), but is stopped somewhere in an intermediate platform (may be at 9:00 of an half sized wheel inside the big one).
Then the smaller wheel drives the weight until 12:00, leaving it at a distance equal to the length of the rope (by the way retrieving its purpose at the right side of the inner rim).
In that case the energy is lost (if the smaller wheel is grounded per example) but the unbalance has not been solved (in contradiction with the principle of conservation)
I cannot imagine why nobody though on this before, including myself? It is so simple!...
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re: The falling elevator and the lost coin...
Hi path_finder,
I vote for, The coin will float inside the elevator (like in the space shuttle), to simulate outer space a airplane takes a free fall dive, where the effects of weightlessness is experienced inside the airplane!
Edit, This is why my multi lever design has a low RPM to give the levers more time to fall.
Also on out of balance wheel Attempts there is a degree of weightlessness as a weight falls and chaos is the result, when I built my velocity shunt wheels this could be seen clearly, as a weight fell there was a out of balance on the opposite side of the wheel, so when the weight hit the bottom of its slot with a bang there was another weight falling so you was working against a negative imbalance and the shunt was lost!
Regards Trevor
I vote for, The coin will float inside the elevator (like in the space shuttle), to simulate outer space a airplane takes a free fall dive, where the effects of weightlessness is experienced inside the airplane!
Edit, This is why my multi lever design has a low RPM to give the levers more time to fall.
Also on out of balance wheel Attempts there is a degree of weightlessness as a weight falls and chaos is the result, when I built my velocity shunt wheels this could be seen clearly, as a weight fell there was a out of balance on the opposite side of the wheel, so when the weight hit the bottom of its slot with a bang there was another weight falling so you was working against a negative imbalance and the shunt was lost!
Regards Trevor
Last edited by Trevor Lyn Whatford on Tue Feb 08, 2011 10:23 am, edited 1 time in total.
I have been wrong before!
I have been right before!
Hindsight will tell us!
I have been right before!
Hindsight will tell us!
re: The falling elevator and the lost coin...
P_F .. I answered the coin falls to the floor.
Here's my reasoning, rightly or wrongly ?
The elevator accelerates until it reaches terminal velocity - that is a very fast rate of descent - the car weighs a lot & the proportion of air resistance on the bottom of the car is small - therefore the car has a higher terminal velocity than say an exact same car a quarter the weight - that's because in the lighter example the proportion of resistance to weight is greater & so the terminal velocity is less.
Now lets look at what happen to the coin inside the car.
It will be accelerated at the same rate as the car - that's because the forces are different for both car & coin but the masses are different, BUT the acceleration is the same.
Now we have to look at the situation inside the car - the coin is not subjected to nor has to be slowed down by the air resistance that the car experiences, because its sheltered inside the car - still it must experience some local air resistance if it moves downwards.
Will it move downwards ?
I think so - the reason is this - the car reaches terminal velocity with losses from air resistance acting against gravity - providing the proportion of air resistance to weight of coin is less than the car experiences then the coin should have a faster terminal velocity & thus move towards the floor.
N.B. this assumes it falls edge on to the direction of fall, the answer might be different if it fell face on ?
Here's my reasoning, rightly or wrongly ?
The elevator accelerates until it reaches terminal velocity - that is a very fast rate of descent - the car weighs a lot & the proportion of air resistance on the bottom of the car is small - therefore the car has a higher terminal velocity than say an exact same car a quarter the weight - that's because in the lighter example the proportion of resistance to weight is greater & so the terminal velocity is less.
Now lets look at what happen to the coin inside the car.
It will be accelerated at the same rate as the car - that's because the forces are different for both car & coin but the masses are different, BUT the acceleration is the same.
Now we have to look at the situation inside the car - the coin is not subjected to nor has to be slowed down by the air resistance that the car experiences, because its sheltered inside the car - still it must experience some local air resistance if it moves downwards.
Will it move downwards ?
I think so - the reason is this - the car reaches terminal velocity with losses from air resistance acting against gravity - providing the proportion of air resistance to weight of coin is less than the car experiences then the coin should have a faster terminal velocity & thus move towards the floor.
N.B. this assumes it falls edge on to the direction of fall, the answer might be different if it fell face on ?
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re: The falling elevator and the lost coin...
Hi Fletcher,
The car is experiencing a high pull from gravity which it cannot match on its horizontal plain , if you dropped it out of a airplane then it would be very different inside the car although the air drag would slow it down so it would seem it is a bit of a trick question, as a lot would depend on just how ventilated the elevator shaft was, and whether or not it a true free fall was meant.
Regards Trevor
Edit, Add missing words.
The car is experiencing a high pull from gravity which it cannot match on its horizontal plain , if you dropped it out of a airplane then it would be very different inside the car although the air drag would slow it down so it would seem it is a bit of a trick question, as a lot would depend on just how ventilated the elevator shaft was, and whether or not it a true free fall was meant.
Regards Trevor
Edit, Add missing words.
I have been wrong before!
I have been right before!
Hindsight will tell us!
I have been right before!
Hindsight will tell us!
re: The falling elevator and the lost coin...
If everything is in free fall then the force of gravity does not act on any object, therefore: The coin will float inside the elevator (like in the space shuttle).
Of course option 5 is the likely end of the experiment no matter what.
Of course option 5 is the likely end of the experiment no matter what.
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re: The falling elevator and the lost coin...
I'm not sure you understood well the supposed situation: the sustentation cable is supposed broken just after the door closure.Fletcher wrote:The elevator accelerates until it reaches terminal velocity
The velocity of the car is therefore without limit (supposing no dashpot effect), increasing with the time (H = V x t and H = 1/2 g t^2).
The reason why I did NOT take in account the air resistance is because this effect is really marginal inside a gravitic wheel of limited size. In fact I had to be more explicite and declare 'without air resistance'.
The poll was just an introduction.
The most important for me was the second post, and the question of the not restitued energy, coming from the not completed free fall.
I cannot imagine why nobody though on this before, including myself? It is so simple!...
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re: The falling elevator and the lost coin...
The coin floats,
But i have another related question,
if your ellevator was taken to 10K feet in the air and you had a device to remove the effecta of gravity on the elevator would.
1. the elevator levitate in air?
2. fly off into space at a super high velocity?
IMHO Fletcher had the best answer but was assuming you were asking a question and knew all the parameters yourself. The air drag is not ussualy considerd if this is asked of high school students but is expected to be included if it becomes a graduate level college class. I have thought fo a while that the effect is one that needs to be completely understood if you want to have a better grasp on the wheel.
Their are lots of really good related videos on youtube that have students testing apparent weight in elevators. NB remember "during acceleration"
Dave
But i have another related question,
if your ellevator was taken to 10K feet in the air and you had a device to remove the effecta of gravity on the elevator would.
1. the elevator levitate in air?
2. fly off into space at a super high velocity?
IMHO Fletcher had the best answer but was assuming you were asking a question and knew all the parameters yourself. The air drag is not ussualy considerd if this is asked of high school students but is expected to be included if it becomes a graduate level college class. I have thought fo a while that the effect is one that needs to be completely understood if you want to have a better grasp on the wheel.
Their are lots of really good related videos on youtube that have students testing apparent weight in elevators. NB remember "during acceleration"
Dave
Si mobile in circumferentia circuli feratur ea celeritate, quam acquirit cadendo ex
altitudine, quae sit quartae parti diameter aequalis ; habebit vim centrifugam suae
gravitati aequalem.
altitudine, quae sit quartae parti diameter aequalis ; habebit vim centrifugam suae
gravitati aequalem.
Re: re: The falling elevator and the lost coin...
There was a young man who said "Godovyyus wrote:If everything is in free fall then the force of gravity does not act on any object ...
Must find it exceedingly odd
To think that the tree
Should continue to be
When there's no one about in the quad."
"Dear Sir: Your astonishment's odd;
I am always about in the quad.
And that's why the tree
Will continue to be
Since observed by, Yours faithfully, God."
Gravity always acts -
all the time -
on every object -
just like God in fact.
Who is she that cometh forth as the morning rising, fair as the moon, bright as the sun, terribilis ut castrorum acies ordinata?
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re: The falling elevator and the lost coin...
Taking the argument I proposed to further depths.
Air Resistance is proportional to the air density & v^2.
So, the car will have greater & greater air resistance the longer & further it falls & terminal velocity is when the air resistance force & force of gravity are in equilibrium.
The coin will have very little air resistance inside the car over a short distance & time period because it can't achieve a great velocity in such a short distance.
This means that the coin would appear to float momentarily then would fall to the floor, IMO.
Air Resistance is proportional to the air density & v^2.
So, the car will have greater & greater air resistance the longer & further it falls & terminal velocity is when the air resistance force & force of gravity are in equilibrium.
The coin will have very little air resistance inside the car over a short distance & time period because it can't achieve a great velocity in such a short distance.
This means that the coin would appear to float momentarily then would fall to the floor, IMO.
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re: The falling elevator and the lost coin...
Dear Fletcher,
Many thanks for your deep explanation, which takes in account all parameters in particular the air resistance.
My intend was to analyse only the effect of the gravity, and almost the behavior of the coin and of the car in the total absence of gravity.
All above postes are extremely interesting but I regret the low level of comments about the most important point : can we imagine a gravity wheel based on the aborted fall of a weight (a kind of Maxwell daemon)?
Many thanks for your deep explanation, which takes in account all parameters in particular the air resistance.
My intend was to analyse only the effect of the gravity, and almost the behavior of the coin and of the car in the total absence of gravity.
All above postes are extremely interesting but I regret the low level of comments about the most important point : can we imagine a gravity wheel based on the aborted fall of a weight (a kind of Maxwell daemon)?
I cannot imagine why nobody though on this before, including myself? It is so simple!...
re: The falling elevator and the lost coin...
I've never managed to find a way P_F that it could be mechanically useful so I'm no help in that regard.