Impact Definition and 956 Threads

Does the institution where an individual receives their PhD degree in mathematics have a significant impact on their career? The question evolves from a merger among universities: If a university is under a merger with another well established university with a much much better reputation in...

Let's say a craft is in an orbit at a height h above a planet or moon. A force acts directly against the craft's direction of motion so as the force vector is always parallel to the surface of the central body. So, the craft will slowly decelerate and impact the surface. What would be the best...

Hi all, I think this question goes best in this section, because I think the answer is something a nuclear or particle scientist could answer. In space, what would happen to a ship that did not have proper shielding from cosmic rays? (NOT the astronauts themselves; there is plenty of...

How many megatons was the pre-historic chixculub meteor impact equal to? This was estimated to be millions of times more powerful than the cumulative explosive power of all of the nuclear weapons in the world combined. It caused the extinction of most life on Earth during that time (namely the...

Homework Statement the vehicle needs to stop as close to a wall that is located anywhere from 9 to 12 m away. (The distance is not given exactly) The vehicle must be self propelled and has other specifications located here...

Ok, so this isn't exactly homework, but it seems the most appropriate spot to post this. A few days ago I (a 220 lb individual) hit an impact from a fall from 3 ft of my entire weight on a single toe against an unmovable object (tile floor) I'd like to know the gforce of that impact...

Homework Statement -- This is out of Rendezvous With Rama by Arthur C. Clarke You know it is 907184 kg and is going 50,000 m/s So how much energy does it have right before it hits the earth? Homework Equations Do I use Fg= Gm1m2/r^2 ? Ek=1/2mv^2? I have ΔE=1/2mv^2 written down as an equation...

The importance of the title "Mathematical Physics" vs. "Physics" for grad school/jobs I've got another quick question for anyone that cares and knows how to help. As I've mentioned elsewhere, I'm a third year physics student, currently enrolled in the "regular", straight-up physics stream...

I been looking on google and getting help from several people who are trying to help me, but I just can't understand this. It is to advance for me as of now and I need a example to help show me. But I need this for homework so can someone help and provide formula explaining how this would. Be...

Why Poisson kernel is significant in mathematics? Poisson kernel is ##P_r(\theta)=\frac{1-r^2}{1-2rcos\theta+r^2}##. http://www.math.umn.edu/~olver/pd_/gf.pdf page 218, picture 6.15. If we have some function for example ##e^x,sinx,cosx## what we get if we multiply that function with Poisson...

Hi, Can you please let me the impact of current loading for the attached circuit? The attached circuit is a 4-stage dc-dc converter- charge pump. When I give an input voltage of 1V, the output voltage is around 4.6 V using cadence simulations. The expected output voltage is 5V. I am...

if you have a beam or something, anchored at one end and apply a moment at the other end, then the bending stress is given by M*y / I, where I is the moment of inertia of the beam. what affect does the length of the beam (i.e. the distance between the anchor and the end of the beam, where the...

Homework Statement A 40kg branch falls 5.5m and lands on a roof. The roof withstood the the impact. Homework Equations If the impact time was 0.4 second calculate the magnitude of the average force exerted on the roof during the impact. The Attempt at a Solution F=ma doesn't seem right...

Lunar Gravity, On the moon, the acceleration due to gravity is $-1.6m/s$ . A stone dropped from a cliff on the moon and hits the surface of the moon $20s$ later. How far did it fall? What is the velocity at impact.? well here I presume since the rock is just dropped that $v_0=1.6m/s$ but the...

Homework Statement The problem is to get the classical turning point as a function of the impact parameter b for the Lennard-Jones potential. Homework Equations The Lennard-Jones potential is given as [itex]V(r)=4\epsilon[(\frac{\sigma}{r})^{12}-(\frac{\sigma}{r})^6][\itex]. The effective...

Hi, I'm having a bit of trouble with the below practice problem from my textbook. The answer given in the back is -9.52 m/s, but there is no explanation. Thanks for any help. Homework Statement Two balls are thrown off of a 7.25 m high building both at an initial speed of 63.5 mph. However...

Homework Statement In class we derived the Schwarzschild interior solution (constant density). Examine the behaviour of non-radial null geodesics in this spacetime.Homework Equations \Phi(r)=ln\left(\frac{3\sqrt{1-\frac{2M}{R}}}{2}-\frac{\sqrt{1-\frac{2Mr^2}{R^3}}}{2}\right)...

Why when got bomb explosion even stand a few ways away,it exploded and the impact can kill a person?

What's the difference between impact speed and terminal velocity? I'm reading a book that gives a shortcut about how to calculate "The speed at impact in the y-direction when falling from rest" and it gives the eguation vt=9.8t.

This is not a specific question. it's just common sense. all temp values in celsius. The impact values of polymers are definitely astonishing when i think at the molecular level it is said that increasing the molecular weight of the chains increase the impact strength. consider same...

is it true that as the lipid water partition coefficient increases, the permeability of lipid increases and the permeability of water lowers. does that mean that a substance w/ a high lipid water partition coeffecient will be able to go through the cell membrane more easily and cause hemolysis...

i had a question PV=nRT is the V the volume of the container or the gas and if it was the container and i had a balloon and i squeezed it decreasing the volume increasing the pressure will that increase the temperature? thank you

Hi Guys, I have been asked to find out at what point a measurement device go out of calibration when dropped and express that in a g as in G force. Its been 15 years since I studied physics (for 3 years), I do rememeber a bit but I need some help.. I have the size and weight (mass) of...

Well, I've never started a political thread on the boards before, nor do I usually get involved in politics because of its persistently unscientific nature, but I feel this topic is of the most profound significance and thus a VERY worthy and eminent discussion. Many in the know would say that...

im new here and found your forum after using google i have a question relateing to a car accident after getting hit by a moped as the insurance company feels that the force could not have caused any damage hopefully someone here can help as it seems a very good forum. my wife was driving her...

Impact ... what? Force or Energy? I have a question, about what to calculate if calculating whether an immovable object (a wall for example) will break or not after an impact of another object into it. What should I calculate, the force of the impact or the kinetic energy of the impacting...

If an asteroid was moving in the opposite direction of the moon, could it slow it down enough when it hit it to cause it to crash into the earth. and vice versa, could it be going the same direction and acceleration it enough to excape the Earth's gravitational pull? If so, about how large would...

Can anyone recommend a device or way I can measure the impact protection qualities of different running shoes? I am a runner and would be interested in doing this myself. I appreciate it!

scenario - A free falling body impacts water at terminal velocity. During what time period is the body considered to be in impact. I am trying to calculate the impact force alone. Is the impact force considered at the initial contact, during the body is fully transitioning from one medium to the...

Homework Statement I am currently conducting an EEI in which I am looking at the effects of increased mass, surface area and air pressure on terminal velocity. In my experiment, I dropped a parachute of 0.36m^2 from a height of 3m with a mass of 0.01kg. My result was that it took 3.036...

Hi All, I'm hoping some of you with more expertise in such matters can help me out with the plausibility of a scenario for a novel I'm working on. I know you guys must get stupid hypothetical questions like this frequently, so if I'm out of line just let me know and I'll just slink back to...

I am doing a simple steel ball drop test on glass to see if the glass passes the standards. We are dropping 1.18 inches (0.535kg) steel ball at the height of 51inches (1.295m). Now, I can calculate final velocity at the impact, but cannot calculate the actual impact force. One of the method...

So I'm trying to figure out a rather amusing problem. A month ago I was doing some work in my attic when I took a wrong step and plunged through my drywall ceiling and fell a straight 20ft to the very bottom of my stairwell landing. I was knocked unconscious instantly and don't remember...

Thought I was done but not the case... Homework Statement Alright so as stated a couple days ago... "projectile is shot from the edge of a cliff 125 m above the ground @ an initial speed of 65 m/s at an angle of 37° with the horizontal from the cliff." ---- As helped earlier I have...

Homework Statement A vehicle falls 20 mm back onto a smooth steel track after going over a bump. It has polyurethane wheels. Young's modulus is known for both wheels and track materials. What is the force exerted by the vehicle onto the track as it lands? Homework Equations F = mdv/dt KE =...

I have a problem that I'm having trouble cracking and was wondering if anybody has any ideas on it. An impact test that we have to do involves swinging a pendulum of weight 50lbs into a rolling easel (for writing on, approximately 6ft high, with casters). The wheels are blocked so the easel...

So I'm supposing a scenario where you have energy transfer into a solid and waves propagating out from the impact point and i want to measure the energy at different distances from the "epicenter" with sensors. the relationships I've been pointed to are basically conservation of energy at the...

Affluence and its effect on society. Does affluence make people lazy and less motivated to strive for excellence in academics ? is there any correlation ? Just want some opinion or articles that i can read.

Homework Statement A cylindrical metal bar of length L hangs by two strings in a horizontal position. The metal bob of a simple pendulum hits one end of this metal bar in a direction perpendicular to the crossection of the bar. Find an expression for the time t of contact during the impact...

Oldest Impact Crater on Earth Discovered http://news.yahoo.com/oldest-impact-crater-earth-discovered-162802443.html The area in Western Greenland has deposits of Ni and Pt. I wonder if it's from the same source as the crater in Sudbury, Ontario, which is considered to be only 2 (+/-) billion...

Is there a way to calculate the impulse force F if the time of collision is unknown? The only formula I know to calculate this force is F*Δt = m*Δv. Is there a formula that perhaps uses plasticity as a variable instead of time or maybe uses the distance an object moves after a collision? Any...

Aim: To understand the physics(equations) behind this problem. On the channel 'Discovery Science',a the show-presenter was testing guns.In one of the tests,he fires the gun at a certain distance from a 'BALLISTIC GELATIN'(just a jelly of high viscosity to simulate swine muscle tissue). The he...

Would anyone know what altitude would be needed within a vacuum in Earth's gravity to create an impact of 4kg using a weight of 70g? Thanks

Hi all 1 ) Direct central impact occurs between a 300N body moving to the right with velocity of 6 m/s and 150 N body moving to the left with velocity of 10 m/s . Find the velocity of each body after impact if the coefficient of restitution is 0.8 . my answer : Given :: m1 = 300...

I'm working on building an enclosure for a machine that is to go on display in a foyer. The machine is about 2x1x1.5m and its primary purpose when switched on is to show how dynamic components work together. My considerations include: Cost: Need something relatively cheap Strength:High...

I am designing my own Charpy impact testing machine and I am unsure what would be the best as well as relatively simple and affordable method I can use to accurately measure the angle the pendulum travels after it has broke the sample. I would also appreciate any complex and more expensive ideas...

Homework Statement Two students threw a paper plane towards the bin, hitting a desk at time t=10. The trajectory can be modeled as follows: x=t-2sin(t), y=4-3cos(t) Then there were a few simple questions before: The students are curious about what would have happened to the paper...

I am a police officer specializing in less lethal weapons. This question has come up many times and is beyond my understanding of physics to explain it. Please help: We use a tool called a PepperBall. It is the same shape and diameter of a paintball. This sphere however is rigid plastic...

i need to work some estimations for this case for an assignment 30mph vehicle hits a bollard with 667kJ bollard height = 1m vehicle hits the bollard at approx height of 0.7m material = mild steel ultimate strength = 400mpa in one case the bollard is 219mm ext diameter with 10mm wall...

Homework Statement A 15000 kg train traveling at 30m/s collides with a 2500 truck with a 90 kg man going at 22m/s in the opposite direction. The time of collision is 1.5 seconds. After collision, both objects are moving in the same direction with a velocity of 22 m/s. What is the size of the...