Impact Definition and 911 Threads

A 1.0 kg object is released from rest 500 km above the earth. A. What is its impact speed as it hits the ground? Ignore air resistance B. What would the impact speed be if the Earth were flat? I don't know how to start this. I said that v=sqrt(2G*M_e*m/(R_e+300))= 1.33*10^9 but that is...

Hi all, How does one calculate the point where impact of a moving object actually begins to move a stationary one, rather than just make noise? Let's keep it simple and assume the objects are of the same material, the stationary one is not anchored, and they won't shatter or explode...

Ok here's my problem: When I put a piece metal in a graduated cylinder filled with water to measure the metal's volume by "water displacement" I see air bubbles trapped under the metal. How do the air bubbles affect the density, mass and volume of the metal piece? Thanks. Need quick answer...

Please Help! I have figured out most of the problems for this assingment, however, I am having trouble with these: 1) A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 21.0 m/s. The cliff is h = 21.0 m above a flat horizontal beach. How...

is a delirium? 1) The photons was influenced by gravity? 2) I think yes, but the light don't lies on earth. 3)The light haves a energy which opposed to gravity. 4)A body with energy in opposite sense of gravity don't feel a speed of a container ( a jump in elevator or other) 5)The...

Has anyone heard of this? http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=39937" Jeez, I'm trying to decipher the website to figure out when to look.

Ball bearings are made by letting spherical drops of molten metal fall inside a tall tower called a shot tower and solidify as they fall. If a bearing needs 4.50 to solidify enough for impact, how high must the tower be? What is the bearing's impact speed? I got the answer for the first...

what causes high tide oppposite the moon?

Hi Please bear with me on this as I’m doing aerospace engineering at college level in the UK, so my knowledge on atomic physics is none to great. What I would like to know is about gravity in a way and yes this has something to do with Quantum physics as well but this is also to do with...

A metal cylinder of 55kg, (0.2m in diameter), traveling at 2.5 km/sec strikes the earth. How big a crater can it be expected to make, given average characteristics for the ground where struck?

A bullet with a mass of 6.00 g is fired through a 1.25 kg block of wood on a frictionless surface. The initial speed of the bullet is 896 m/s, and the speed of the bullet after it exits the block is 435 m/s. At what speed does the block move after the bullet passes through it? For this one...

Hi, I'm trying to figure out how to calculate the resulting velocity vector of a ball after impact with a surface. If the velocity vector is V {Vx, Vy, Vz} and The ball hits a surface with normal N {Nx, Ny, Nz} what would be the resulting vector of the new velocity? Assuming the ball...

Erik Drops a ball from a height of 15.0m above the ground. After it hits the ground it only bounces back up to a height of 13.5m. Erik Catches it at this point, as it is just about to fall back down. just need some quick helping steps to get me started on these questions help would be...

Has anyone here heard of artificial life? It is a growing discipline where the idea is a bottom-up approach of starting with lots and lots of simple systems, and hoping they evolve to show emergent structures. This is at odds with artificial intelligence which is a top-down approach of...

Hi, Supose I drop a body of 7 Kg from a height of 2 meters. Is the impact energy equal to: E = m * g * h = 7 * 9.81 * 2 = 137,34 Joules ? And if it is, is the kinetic energy equal to this ammount? Kind regards, Kepler

it seems a silly question. how to figure out the most important journal in this field? can I serch by the impact factor?how can I use it? I am a beginner in this branch, and I am confused in how to find out the important artical which imapct this field a lot.

Triassic extinction meteor crater in Antarctic Ohio state press release here http://researchnews.osu.edu/archive/erthboom.htm Pictures here http://researchnews.osu.edu/archive/erthboompix.htm possible cause of Permian-Triassic extinction circa 250 million years BP larger crater and larger...

I am doing a dull vocabulary project, and I need to define impact velocity. I cannot find a suitable definition anywhere, although I have an idea. Does anyone have a good definition? My thought is: Impact velocity is the maximum velocity obtained by an object before it is stopped by something...

A tank is filled with water to a height H, 26 m. A hole is punched in one of the walls at a depth h = 6.50 m below the water surface (see the figure). What is the distance x from the base of the tank to the point at which the resulting stream strikes the floor? i knoe the equation to find out...

A quick look through the FAQ and search didn't reveal anything so... I know that K.e. = ½MV², however I am looking to find the energy of an impact when φ != 90°. Or to the more specific problem, if I have a Spaceship shaped like a needle moving through space at .9c(Vnet) and a micrometor hits...

ok i got a question that has come up at work today and we can't come to a answer we all agree on, i won't go into the reason this question came up unless i can't answer questions about it without referencing it so here we go if object A a poll like object as wide as a Object B hits Object...

I know that there are people with the idea that at great scales in space gravity is repulsive. Could someone tell me how this fits with the geometry of space. It is clearly bad news for GR if this is correct. How does repulsive gravity shape the geometry of space if indeed it does?

whats the role of advanced math in a ordinary person' life directly? does it make a big change in ur life wether u know advanced math or not?

Let's do another one. The idea that humans can and have had a big impact on climate is increasingly thriving. Apparently we are the central factor -Anthropocentrism. It started with Ruddiman who had produced a http://courses.eas.uAlberta.ca/eas457/Ruddiman2003.pdf . How come, well the...

This is probably the third time that I have heard or read conflicting reports on this. http://www.rutlandherald.com/apps/pbcs.dll/article?AID=/20060104/NEWS/601040303/1039 http://www.Earth'sky.org/shows/astrophysics_interviews.php?id=49241

Hi guys; Got a question that has me scratching my head. The new server at my favourite hangout is a commercial pilot taking a wee bit of a rest break. The other day she told me that for some reason, the right side of a Piper Navaho always receives the vast majority of the damage in a crash...

How much would a DNA screen reveal about someone's personality and intelligence? :confused:

I read the book and looked through some sites but I don't seem to understand. I have a lab soon and I have to answer this question. What must be responsible for the pattern of tides that you see? Why? a. The moon orbits the Earth once each day. b. the Earth spins on its own axis once each...

My problem is as follow! A 45kg dog that is leached, starts to run and the line is all out when he have reach the speed of 20 m/s. The owner will experience a tweak. How do you approximate, this tweak? My thinking is that it depend on how fast the deceleration are, according to this...

hi, thank you for helping For same momentum change if we increase the time of impact by factor ten then force is smaller by factor ten. But why is that? I mean why doesn't a moving object at point of impact give away all of its momentum at the instant it hits something,no matter if that...

A boy with a weight of 70 kg jumps down from a 3 meter high tree. His velocity on impact I have found to be 7,68 m/s and the impulse is 536,7kg*m/s. Now I need to find the average velocity during impact. What formula do I have to use?

How would you accurately estimate the force of a car crash? Say, a 2,500lb vehicle has an impact with a wall @ 30mph.. How would you accurately estimate the force in LBS, Is it possible?

What advance in physics do you feel has had the greatest impact on history? This is a question I have to answer for a research project. Currently my plan is to do John Bardeen and the transistor but I'd like to here some other ideas.

Hi Can someone edit my intro for my history essay? This is a very very very very...very important essay so please be as [productively] critical as possible. this is the prompt: "To what extent did "Yellow Journalism" influence the United States decision to declare war on Spain?" (this...

From a thread in engineering: My point is this: though the Earth accelerates the feather and the ball bearing equally, the feather and the ball bearing do not accelerate the earth equally. As a result, the time to impact for the ball bearing will be less than for the feather. For objects that...

if Planck's constant were smaller than it is, shouldn't quantum phenomena be more obvious than it is now?

Hi everyone. I'm not a physicist but I need some help. In the hypothetical situation of a 1 kg block of concrete being dropped onto a concrete slab from 3 metres, the force of the impact is easy to calculate. However, if one were to pick up the pieces and re-drop them, what would be the force...

What are some scientific ideas you think had the greatest impact on society? It'd be nice to have a few that aren't "obvious." (don't mention the transistor :-p)

the universe is expanding. The space between particles of an object is also expanding. So will the force of expanding eventually break the attractive force between particles? stupid question.. help me please anyway thanks

So, I searched and found one almost identical to this, but no direction towards solution was posted, and I couldn't make sense of the formula in the original post. So... A red train traveling at 72km/h and a green train traveling at 144km/h are headed toward one another along a straight level...

How does ST vary with temerature? Is there a mathematical relationship? Also, does the sound water make on splashing have anything to do with its ST?Like,hot water makes a different sound from cold water etc.

Last year I completed two courses in the space of one, so this year I may have the possibility of having a free period. I was just wondering if having a free period looks bad to universities even if I have all my credits.

A paper just came out this month that makes it more certain that the Cosmic Microwave map will have to be revised, with even less quadrupole and octopole power. http://www.arxiv.org/abs/astro-ph/0508047/ On the large-angle anomalies of the microwave sky I opened a thread on this paper in...

What do you think about this term?

1. In general relativity, why is there a requirement for spacetime, in the context of the Universe, to expand/contract? It is often said that the theory predicts the Universe to expand, but Einstein missed out on this by adding the 'cosmilogical constant'. But where in the theory is the...

If I decrease vf, will I deliver greater impulse?

does anyone know the reason why they used a copper "impactor" for the deep impact mission? is it for its corrosion resistance? thanks

Reminder about "Deep Impact" on night of July 3 http://science.nasa.gov/headlines/y2005/images/deepimpact/skymap_north.gif here is a skymap NASA will send this 820 pound copper slug into the guts of comet Tempel 1 at 11 PM Pacific Daylight Time on 3 July For people with home...

This is a simple(?) problem but my ability to perform basic calculus disappeared long ago. I am working thru the equations for a spring response to a dropped weight. My primary reference is Shigley (for just about everything!) and I've validated the eqn's for deflection and max force. However...

a compressed spring is completely dissolved in acid what will happen to the elastic potential energy of the spring? With reasons. I think that the E.P.E will have an effect on the heat released but I still don't have backup. I am still not so advanced.