Impact Definition and 911 Threads

Could someone please help with this rudimentry calculation. I need to know the difference in the energy at impact between the following two scenarios. 1) 2 lbs falling under gravity from 8 feet with an impact area of 12 mm. 2) 4 lbs falling under gravity from 4 feet with an impact area of...

Is the struggle to reach beyond relativity and quantum mechanics, beyond the big bang, possibly its creation and necessity to our logic, the result of structural problems with mathematics itself? The fundamental unit of maths is numbers, is it not? The discovery of zero or its inclusion in the...

In this problem, you will estimate the cross section for an earth-asteroid collision. In all that follows, assume that the Earth is fixed in space and that the radius of the asteroid is much less than the radius R of the earth. The mass of the Earth is M_e, and the mass of the asteroid is m. Use...

On a frictionless table, a glob of clay of mass 0.740 kg strikes a bar of mass 1.740 kg perpendicularly at a point 0.140 m from the center of the bar and sticks to it. If the bar is 0.660 m long and the clay is moving at 9.600 m/s before the impact, what is the final speed of the center of mass...

Is the spin of an atom come from (or based on) the Nucleus (i.e. net of Neutrons and Protons)? With the spin of the Electrons not really noticed or counted though a sense of being ‘lost’ or masked by being in an orbital?

I wonder how could I calculate impact force of an object (eg. a stone) in a free fall impacting on the perfectly inelastic (perfectly hard) floor. I know: - m -mass of the falling object - h -height of the fall - v -speed at the time of impact - t -time it...

I live in Northern Ireland, and we have many different groups of people that all listen to different / mixed types of songs. I have observed for quite some time now (Years) that certain people that listen to certain music behave in certain ways. The biggest impact music has had in Northern...

Hello, could someone please help me out with the following question. Q. A person suggests that if you are in lift, which is falling due to the connection cable having previously snapped, you can avoid injury by jumping up just prior to the lift's impact with the ground. Comment on the...

Hi all, I've been doing a lot of research recently, but am still struggling to do a good hypothesis for my experiment. The experiment is to find the efficiency of a ramp. I will be changing the height of the ramp and will be measuring the force required to lift a bucket with a total mass...

In the Rutherford scattering experiment a very thin gold foil target is bombarded with a beam of a particles of known kinetic energy. A detector which can be moved on a circle around the target counts the scattered particles. What was the impact parameter of a 4.57 MeV a particle if it was...

During most of the 19th Century physicists believed that atoms were the smallest particles of matter and thus couldn’t be further subdivided. With such characteristics, an atom of one element obviously couldn’t become an atom of another element – a process they labeled “alchemy”. J. J...

Hey.. i was wondering how math ( especially algebra ) could be used in gathering information about it that could help in its prevention? what are the formulae, if any, that can be used to find the distance/height, impact ,etc of the tsunami? thanks

Ok, we were doing a lab yesterday in physics class, and we had to find the velocity of a bullet hitting a block with a hole in it's center, and is hung... when the bullet hit the block, it made a 18 degree angle... my teacher gave us a formula for finding the velocity of the block and we got the...

a wooden peg is hit vertically by a mallet which is also moving vertically. The mass of the peck is 0.4kg and the mallet is 2kg. The speed at which the peg starts to move into the ground is 6.67m/s. Given that the ground opposes the motion of the peck with a force of 1kN, find how far the peg is...

So is it going to happen? what will be the consequences if it does happen, will we suffer a multi pole magnetic field for hundreds of years? some say that cancer will increase at the multi poles and that thousands of people will die as a result, so who cares about global warming if a new...

I want to take a look at the history of philosophy. I would say it's a look at the history of "philosophy of mind", but it covers more than that. I want to look at the points throughout history where a shift was made, to the using of terms and concepts that had never been used before. I want...

If someday we discover how to mine metals from the core, will it have any effect on the magnetic field or the climate of the Earth due to reduction of heat in the core as the metal mined will be hot and will slowly drain the heat of the core.

Reference: http://www.harktheherald.com/modules.php?op=modload&name=News&file=article&sid=45033&mode=thread&order=0&thold=0

Launched today at 1:47 pm. Impactor will hit comet Tempel 1 on July 4. Love the real-time blog for the launch... http://www.space.com/missionlaunches/delta2_launch_050112.html

Deep Impact Mission Sounds Scary? I don't like this misson. There are better ways to study this thing. Land on it and do the probing! Just what we need to do. Blow this thing to bits so it can rain down on us,possibly.It ain't worth the chance. "The impact spacecraft will fly head-on into...

I need some help from the experts, because I am really having trouble simulating this in the real world which is where I can understand things. If propane gas was released from a container (typical metal propane tank or cylinder) where it had been stored as a liquid under pressure, it would...

Hi, sorry if this is posted someplace else - I couldn't find a search function. I want to know the force of impact of a Porsche 911 impacting a standing pedestrian at 95 mph. I understand that F=m*a But what I don't get is this: acceleration is measured here in mph. But the impact...

In the Astronomy Events thread, Check is citing odds that are even worse now! http://space.com/scienceastronomy/asteroid_risk_041224.html Those odds are getting a little close for my taste.

Hey, anyone seen this incredible photo?? Impact pic Much larger pic APOD article http://www.news.com.au/common/story_page/0,4057,11480527%255E13569,00.html It appears to be the first ever recorded image of a meteor impacting the Earth (though for some reason, they're saying...

In a closed system a hydrocarbon is burnt. The products which are produced have a temperature of X degree celcius. What will happen once the temperature of whole of the system becomes X degree celcius? How will it affect the burning of hydrocarbon? Thanks a lot for any help. Abd. S.

A 4.2 g lead bullet moving at 260 m/s strikes a steel plate and stops. If all its kinetic energy is converted to thermal energy and none leaves the bullet, what is its temperature change? --- I don't even know what formula to use or how to start. I could get force, by multiplying the mass...

Does rotation of the earth, become a variable in the quest for the theory of gravity?

Hi Arcsin width/length of a water droplet on any surface will give you the angle between the droplet trajectory before falling (assume straight line rather than parabola) and the surface upon which it fell. As this angle approaches 90degrees (water drop falling vertically on a horizontal...

Hi there. I was wondering if the universe is curved or if it is flat. By the way, one other question. When a person lifts an object the object gains Ep. Is the energy given to object by the person or does it gain energy by the Gravitational Field? even though i know that Forces...

Just a question I am a little stuck on. I missed last week's chem lecture: What effect would each of these changes have on global warming? a) volcanic eruptions b) CFCs in the troposphere c) CFCs in the stratosphere Here's what I think so far.. a) Volcanic eruption release large...

A meteor has a speed of 83.0 m/s when 811 km above the Earth. It is falling vertically (ignore air resistance) and strikes a bed of sand in which it is brought to rest in 3.31 m. What is its speed just before striking the sand? So here is the formula that I have but it doesn't give me the...

Hi, I need help solving this problem. On one hand, I think that there's not enough information to solve it, on the other hand, I think there has to be a way to cancel out all the information that's not provided, and do the problem with only what's given. But I can't come up with a way to solve...

A golf ball (m = 38.6 g) is struck a blow that makes an angle of 46.3 degrees with the horizontal. The drive lands 273 m away on a flat fairway. The acceleration of gravity is 9.8 m/s^2 . If the golf club and ball are in contact for 10.2 ms, what is the average force of impact? Neglect air...

How much does one have to smoke to have a noticable impact on their health? How often does one have to heavily drink to have a noticable impact on their health? Always have been questions i never got around to asking.

I need help on how to approach this problem and which equations I can use. It was a problem that we were supposed to think about, but even that's difficult. Here it is: If there is a 70 lb. girl roller blading at a constant speed of 5 mph and she suddenly hits a rock and trips downward, what...

A typical car with a dummy crashed into a wall, what is a suitable parameter for the head of the crash test dummy(with and without restraints) as a function of time? and how do i estimate the forces acting on the head in the two situations? Thanks a lot :confused:

I am trying to understand how Space and time Relate with Gravity. In Physics class i saw a video showing planets Rolling around on a grid with the sun Making the deepest indentation and planets making smaller ones. Now I can but help thinking that this didnt give me the full picture .. Is it on...

Is it true I have more chance of expiring from a global cotastrophe in the next 50 years as a result of a terestrial object from outer space colliding with Earth than winning the powerball with a $1 ticket.

a 0.3 kg ball moves toward a bat with a velocity of 50 m/s [E]. It is struck and the bat remains in contact with the ball for 0.02 seconds. The ball leaves the bat with a velocity of 100 m/s [W]. Calculate the average force exerted on the bat. (answer: 2300 N) ...i am just horrible at these...

This may be more of an engineering question, but here goes: I am designing an archery target and am trying to establish the impact force of the arrow on the target. The arrow is traveling at 100.6m/s and weighs 22.68g, what would be the force of the arrow on the target? How does this...

I’m just wondering if anyone’s heard about this? http://www.rense.com/general53/rumor.htm http://www.freerepublic.com/focus/f-news/1128284/posts & http://www.bushcountry.org/news/jun_news_pages/g_060104_withheld_june_2004.htm And you can google for “Snowball intercept” and get lots of...

Hi- I have a quiz tomorrow on Newton's 1st and 2nd Laws. I'm kind of iffy with the second law, especially when it comes to impulse and impact. What is impact, and how can you measure impulse? For example, what if an object is dropped onto a soft couch, etc, etc.. basic theories... i haven't yet...

how do humans effect the results of carbon 14 dating, or how do we change the rate of production of carbon 14(chage the ration of C-12 to C-14)?

Hi can anybody verify if I am using the correct formula, Here is the problem first, A bullet embeds itself in a pendulum bob, and the bullet+bob together swing up to some maximum height, which is easy to measure. IF the bullet has a mass of 15g, the bob's mass is 4kg, and the combination...

I am trying to find the kinematics of a car collision with a wall. To calculate the damages, should I take into account the momentum or work done? In other words, is this proportional to velocity or square of the velocity? Thanks, Venkatesh

A frequent topic of debate for golfers is the initial direction that the golf ball follows when it is struck with the club face angled right or left relative to the direction of the moving clubhead (i.e., an "open" or "closed" face for those familiar with golf terminology). The common belief...

I'm really fired up about physics now. But I can't puzzle out the following: Q. When you float in fresh water, the buoyant force that acts on you is equal to your weight. When you float higher in the high-density water of Salt Lake, the B.F. that acts on you is actually: 1) greater than your...

http://news.bbc.co.uk/2/hi/science/nature/3517319.stm

I would have to say the "Roe vs Wade" case. It has contributed to mass genocide (fetuscide?) of tens of millions of "could have been Americans". In this group would have been countless Teachers, Doctors, Scientists, Engineers, etc. Maybe one of them would have found a cure for cancer, who...

if there's two identical object of the same mass and same composition but is of two different colours, would one weigh heavier than the other?? assuming that the coating of paint that gives the object its colour is of the same density for each colour and that same volume of each colour is used...