then, choose the correct option-
(a) the hollow sphere reaches the bottom first
(b) the solid sphere reaches the bottom with greater speed
(c) the solid sphere reaches the bottom with greater kinetic energy
(d) the 2 spheres will reach the bottom with the same linear momentum.
the correct answer, according to my book, is (b) option……can u explain why….? feel free to use torque, moment of inertia, etc etc….in ur explanation……
Posted in Solar Power
Tagged correct option, hollow sphere, inclined plane, mass, option, plane, radii, sphere
Galaxies and solar systems tend to have a disc-like configuration. That is, the orbiting planets (in a solar sytem) and stars (in a galaxy) predominantly revolve around the center on a single plane. Why?
Clarification….why do they revolve in a single plane (to form a disc) instead of randomly in all directions (to from a sphere)?
Posted in Wind Power
Tagged center, CONFIGURATION, galaxies, galaxy, plane, planets and stars, solar systems, solar sytem, sytem, tendency
Do other solar systems move this way too?
Posted in Wind Power
Tagged plane, planets in our solar system, solar systems, sun, system, way
Do other solar systems move this way too?
Posted in Wind Power
Tagged plane, planets in our solar system, solar systems, sun, system, way
Here’s a question: Does Tony Blair get to bring his laptop on his government plane? Can Laura Bush keep her lipstick with her on Air Force One? Does Dick Cheney take off his shoes and get them x-rayed before he flies? How about Condi Rice’s knee-high lace-up boots? Is her mission to Israel delayed while she tries to re-lace them while balancing her laptop bag on one shoulder and trying to get her watch back on?
It seems to me like our glorious leaders are pretty good at setting out the “minor inconveniences” that the rest of us have to put up with, but when was the last time you heard of any of them enduring the same measures?
Now, GW Bush may say, “But I’m no terrorist! Why shouldn’t I be able to bring my hip-flask onto Air Force One with me?” But I’m no terrorist either. I don’t see why the man should be exempt from his own rules. If it’s sauce for the goose, it’s sauce for the butcher.
These people tell us that these are the necessary austerity measures in the extraordinary times. If FDR told us to fast on Wednesdays and turn our furnaces off on Fridays to help the war effort, I’d expect him to do the same, even if he had a bunker full of canned goods and his own private free energy heater. As far as I can tell, 100 percent of the “security measures” to “fight terrorism” apply to 0 percent of the people who makes those decisions.
Posted in Solar Power
Tagged air, air force one, Condi, condi rice, Dick Cheney, force, Government, israel, knee high lace up boots, lace up boots, laptop, laura bush, lipstick, liquids, mission, plane, question, Rice, shoes, tony blair
1. A Boeing 767 travelling at 590 mph has more energy than a Boeing 757 travelling at 530 mph. (Bigger plane – more mass, higher speed, therefore more kinetic energy). Also walls of reinforced concrete and steel can sustain greater impact than sheets of glass and steel. How did the 757 plowed through more than 235 feet of concrete and steel (Pentagon) and the 767 couldn’t even go through 208 feet of glass and steel (WTC tower 2)?
2. A 1368 foot tall building with 110 floors (approx 12.44 ft per floor) takes 96.9 seconds to collapse under the “pancaking” or “progressive collapse” theory. The WTC towers took close to 10 seconds. 9.25 seconds is the free fall time from the top of the towers. I have explained this in the section below.
3. Gravity on the earth’s surface points downwards. If no other forces are introduced and the resultant is still vertically downwards, why are there plumes and projectiles going sideways and upwards in the videos of the WTC collapse?
The pancaking implies that the top floor collapses on the floor immediately below it and that impact makes the lower floor collapse as well. This implies the second floor from the top can’t start moving till the top floor has reached it after falling through 12.44 feet. The third floor can’t start moving until the 2nd floor reaches it.. and so on. So each floor has to fall 12.44 ft independently before the floor below it collapses. Adding the time taken for this “progressive collapse” you get 96.9 seconds.
enginerd, I see most of the answers you have written are outside the realm of science. I suggest you stick to those fields. No one is claiming perfect knowledge, and the questions I asked are not extremely detailed either. And Occam’s razor (catchy term, huh) has been applied to arrive at these questions. If two projectiles with different energies hit the same material the one with more energy will penetrate further. Occam’s razor right? So obviously the deeper hole was made by something with more energy.
I already explained #2 in detail. The assumptions are extremely unfavorable to me. This model assumes that a floor starts moving as soon as the one above it reaches it. In reality the whole fracturing would take some time and would INCREASE the total time. This model calculates the LEAST time it should take.
#3 really couldn’t be any simpler, right? Might I mention conservation of energy? Or was that an optional topic where you learned your engineering?
Just a side note: I have a degree in rocket science (or aerospace engineering in more mundane terms.) And how long it took for the structure to collapse: 8-12 seconds. Source: Official 9/11 commission report and lots of video footage. Not happy? Ok I’ll assume 15 seconds. Still nearly 6 times as small as 97 seconds. It’s a difference of 5-10 seconds. It’s more than a multiple of 5.
For some people I think I need to see your diplomas before I even start reading your answers. Hehe..
Posted in Solar Power
Tagged background, boeing, boeing 757, boeing 767, concrete, concrete and steel, energy, glass, kinetic energy, mass, MPH, pentagon, plane, political question, question, reinforced concrete, Steel, tower 2
1. A Boeing 767 travelling at 590 mph has more energy than a Boeing 757 travelling at 530 mph. (Bigger plane – more mass, higher speed, therefore more kinetic energy). Also reinforced concrete and steel can sustain greater impact than glass and steel. How come the 757 plowed through more than 235 feet of concrete and steel (Pentagon) and the 767 couldn’t even go through 208 feet of glass and steel (WTC tower 2)?
2. A 1368 foot tall building with 110 floors (approx 12.44 ft per floor) takes 96.9 seconds to collapse under the “pancaking” or “progressive collapse” theory. The WTC towers took close to 10 seconds. 9.25 seconds is the free fall time from the top of the towers. So what force accelerated the collapse of the towers?
3. Gravity on the earth’s surface is a unidirectional force : DOWNWARDS. Why are there plumes and projectiles going sideways and upwards in the videos of the WTC collapse?
Don’t merely cry “conspiracy theory”. Provide scientific reasoning.
There are many more. But let’s start with these 3.
INFTCCO, I asked for SCIENTIFIC explanations, not your out-of-the-ass opinion. Which part of that didn’t you understand?
I am not implying anything. I have studied science and I have noticed anomalies, although I am neither the first one nor the only one. There are many prominent members of our society who have the same questions as well. I just want scientific explanations, preferably from the conservatives, to explain away these anomalies.
I have put some numbers out there based on calculations. Any explanation without adequate calculation will be deemed invalid. Science is all about numbers. So cut out the crap.
Leogirl, you don’t seem to have any understanding of science and I will not grace your uneducated response with a comment, except that I didn’t skip science classes, I have an engineering degree. Thanks for asking.
Danny, the time calculated for an object to fall a certain distance has little to do with its mass, size or shape, unless the drag caused by air is comparable to the weight of the body (terminal velocity case). And you also didn’t get the last question it seems. There was NO resultant force to start with that can move something upward. You cannot create something from nothing. If things moved upward, WHAT created that force? Do you know the meaning of RESULTANT.
I will not comment on any more answers. Please, if you don’t have a basic understanding of science, don’t try to answer my question.
Posted in Solar Power
Tagged anomalies, boeing, boeing 757, boeing 767, concrete, concrete and steel, conspiracy, conspiracy theorists, energy, glass, kinetic energy, MPH, Official, pentagon, plane, Steel, tower 2, Unofficial