Wouldn't the air's weight be held and cancelled out by the roof of the building?
120599
Let me ask you a question:\nNormal Air Pressure is 14.7 pounds per square inch. So if i take a book sized square card say 5 inches on a side:\n\nIf i weigh this card flat face up, will it weigh 300 pounds more than if I weigh it sideways? you know from experience, that it isint so. but why?\n\n\nThe answer to both these questions, lies in the fact that air pressure DOES NOT act downwards. It is equal in all directions. \n\nIn fact, there is an experiment conducted to teach airpressure to kids: fill a glass with water till the brim, place a card over it so that the card touches the surface of water, now overturn the glass and the card does not fall off even with the weight of water on it. pictures here:\nhttp://www.stevespanglerscience.com/experiment/00000058\n\nin this experiment airpressure actually acts upwards!.\n\njust because you are sitting under a roof, the air pressure acting on you does not reduce. the air around you is being squeezed inwards by the air outside your house, which is being pushed downwards by all the air above it.\n\nInfact airpressure does not contribute to your weight at all becase it is pushing you upwards as well as downwards with equal force.\n\nSo you weigh the same indoors outdoors, flat side up, or sharp side up
467507
the answer above is wrong to a degree - in your example i would have to imagine falling through a vacuum therefore if he didn't touch the sides his momentum would carry him to the other side and then back again over and over\n\nthe answer above ( 1st ) assumes air resistance would slow him down but he would go back and forth for a long time before stopping\n\nthe gravity would decrease on the way down and increase on the way up but not in the way you think what would happen is that the gravity would be pulling from the side more and more the deeper you got ( so the effect is only virtual) you would always be in a 1g field it is just the direction(s) of the pull that would change\nthe direction of the most mass at any one time would appear to be down and at the center all pulls ( 360 degrees ) would seem to cancel one another ( but they would still be there )
444536
Bingo!!! You got it...air resistance.  If you dropped them in a total vacuum, they would both fall at the same rate.
216112
Well, yes, neglecting any energy loss to friction (e.g. air resistance)
616273
One of the TV specials indicated that the WTC was designed to take the impact of jet plane.  However it was smaller one than what hit it.\n\nObviously each tower was able to absorb an impact above what it was designed for.\n\nThe near full load of jet fuel in the plane ignited and with the sprinklers not function due to the impact, the intense heat of the fire soften the structural beams.\n\nEventually the structure, already damage by the impact, failed because the reaming steel became too weak
613063
What you are saying is possible, yet the weight or gas would have to be escaping from earths atmospere or else the mass is still there.  It is a very intetresting idea, though.  \n\n If the weight of the earth dropped then the distance between the earth and sun would increase since the mass is directly proportional to the force between them.
254102
Dont know about in the USA but in the UK airspace is "such height as is necessary for the ordinary use and enjoyment of the land and the structures upon it" Lord Bernstein of Leigh v Skyviews & General Ltd, and the ground under land is owned although any minerals found will likely be owned by the state
524096
If you idealize the motion without any resistance and an idealized spring representing the bungee cord, then the potential energy lost in the drop of the student from the bridge to the river is\nm*g*y(0)\n\nThe energy then stored in the bungee at the moment the velocity of the student is zero, is:\n.5*k*(y(0)-y(e))^2\n\nthis includes the earth, the student, and the bungee cord, and the relative vertical distance from the bridge to the river.\n\nThe other factors such as the moon and the sun will have negligible effect on the student's motion.\n\nAir resistance could be a factor depending on the distance from the bridge to the river.  Since air resistance creates a drag force, there will be energy loss due to this force which will reduce the extension of the bungee cord resulting in a hand in the water versus a face plunk.  F=d*v^2\nThe terminal velocity of a skydiver presenting maximal area to the fall is about 40 m/s, which requires more than 800 feet of free fall.  Since the maximum velocity occurs in the early stages of deccelartion due to the force of the bungee, air resistance is unlikely to be a major factor.  The highest bridge in the world is Royal Gorge, Colorado U.S.A. , which is 950 feet from road surface to the gorge floor.  If the bored college student forgets to attach the cord, they will plunge into the ground at about 95 miles per hour.\n\nHeating the bungee is unlikely to be a factor since the cord is relatively light and suseptible to melting.  The amount of heat that would be measurable as a loss in potential energy would likely cause spontaneous combustion in the cord.\n\nj
152587
YES INDEED !!! It's really not that hard to get to the roof , we have a staircase that leads to it ( it's flat , the roof that is .)
91784
The concrete blocks you saw at the end were counterweights.  Without the counterweights the crane would fall over or just be unable to lift anything that amounted to anything.  A crane's capacity lowers as the weight of what it is lifting moves farther from the counterweight.  A crane might have a 20 ton capacity if it's boomed all the way up or if the load is as far in as it will come but it won't be able to lift that same load farther out (the working radius).\n\nAlso there are a couple of systems by which the crane can lift itself higher.  One is where they have hydraulic lifts and will lift itself up and insert a new section.  The other is where the crane is actually attached to the building and does something similar.
604436
actually, it can! If you understand physics, the website below has proof. (but I dont know how hard you threw it.)
584229
yea...as long as a big puff of wind doesnt come along and blow you away
60207
AIR RESISTANCE CANCELS OUT THE FORCE DUE TO GRAVITY , THERE IS NO ACCELERATION BECAUSE THE OPPOISTE FORCE IN THE SAME.\nSO YOU CAN SAY 0
224225
yes i think so because the mass is more and it would at a greater height due to momentum, this is only apprecable if u create pressure in side.
438235
That's like living above Mount Everest.  No, it is not possible.\n\nhttp://bmj.bmjjournals.com/content/vol317/issue7165/images/large/abcoxy5.f2.jpeg
218060
I'm assuming it's okay to neglect air resistance in this problem, and that the vertocal velocity component you requested is right before the thingy (I love the word "thingy") hits the ground.\n\nWe have the kinematic equation: S=160+V(initial)t+.5at^2.\na is -32 ft/sec^2, and the initial vertical velocity is 0, so we have S=160-16t^2.  When it hits, S=0, so:\n\n160-16t^2=0 --> 16t^2=160  -->  t^2=10  -->t=10^(1/2)\n\n(Or t = (square root of ten) seconds.  About 3.16 seconds.)\n\nNow that we have t, we just multiply that by the horizontal velocity:\n\n960*10^(1/2), or 960 square root of 10.  (In feet.)  \n\nTherefore the object will land 960*10^(1/2) feet from the base of the building.  Roughly this is about 3035.78 feet.\n\nTo get the final vertical velocity, we use the equation:\n\nV(final)^2=V(initial)^2+2a delta S.  \n\nChange in S in the vertical direction is -160 ft, and a=-32 ft/second squared, and V(initial)=0, so:\n\nV^2=2(-32)(-160)=10240 ft squared per second squared.\n\n--> V=32*10^(1/2), or about 101.19 feet per second.\n\nI hope that's correct.  I typed it with one hand while not really paying attention.  ^_^  From now on, do your own homework.  :P
432236
it seems crazy that sky scrapers can be so high and not fall down on their own.  this is because it is full of materials that have been tested before to failure.  the structural engineer knows that every beam, joist or member has a certain design load capacity.\n\nby figuring out what the design of the building is, what materials will be used and what the different loads will act on the structure, the structural engineer will be able to adequately design a system that can carry the load.\n\nfor example.  a 5 story building is to be built.  the soil needs to be tested to see if it can support the foundation.  depending on how many people will load the floors, structural beams will be designed to support such loads and more.  most structural systems have been done and tested before so there is plenty of documented evidence that a certain structural system will work.\n\nnot to mention that many structural engineers now build their work virtually.  they can apply different simulations e.g. seismic loads to see if their calculations work and see it virtually withstand the loads.\n\nhope this helps.