Crash Definition and 206 Threads

  1. Username34

    I Airplane crash probability fallacy

    https://anxieties.com/self-help-resources/fear-of-flying/how-safe-is-flying/ "In fact, based on this incredible safety record, if you did fly every day of your life, probability indicates that it would take you nineteen thousand years before you would succumb to a fatal accident." The...
  2. B

    Automotive Examination of an automotive crash test

    Given { KE=.5M(v^2)} the act of ramming a car into an immovable barrier and the loss in speed from first contact and when the car totally stops, can be described as exponential in nature. Just like that of a Capacitor discharge curve. is that plausible, or for that matter solid accurate?
  3. J

    B Car Crash Physics: Deceleration Calculations

    Hi, I was watching a documentary on car crashes and how designs are continually being optimised to keep passengers safe. They were saying how many ‘g’s’ certain crashes were based on crumple zones, seatbelt stretch etc. I was interested to do some number crunching to see how big the...
  4. M

    B What if a needle hits Jupiter at nearly speed of light?

    This is much like the "grain of sand" at near speed of light hiting Earth, but now targeting Jupiter with a needle! What if... Any way, which is the correct way to analyze this kind of scenarios? For example, I think than being the speed of the needle near c, is nonsense to think about the...
  5. D

    Did my Android program crash because it lacks a delay mechanism?

    Hi everyone I modified some code that originally displayed a toast when the screen was pressed and held. The original code used onTouchListener with a relative layout, but I changed it to a button instead. I think I've copied it correctly, but my program crashes when the button is clicked. I...
  6. Jarvis323

    Should we brace for a stock market crash?

    There is a lot of talk about the risk of a major stock market crash in the near future. https://www.businessinsider.com/stock-market-crash-wall-street-2023-us-economy-avoids-recession-2022-11?amp Are you bracing for this, and if so how?
  7. russ_watters

    Boeing China Eastern 737 Crash: What Caused the Unusual Cruise Phase Tragedy?

    On Monday, 3/21 a China Eastern Airlines 737-800 crashed, killing 132 people. What is unusual about this crash is that it happened from the cruise phase of flight. This is usually the safest phase, as the plane is flying straight and level most of the time and nothing is changing so there...
  8. shivajikobardan

    Comp Sci Learning Pseudocode: A Crash Course for Beginners

    I found pseudocode for this problem below-: def minimax(current node): if is_leaf(current_node): return static_evaluation(current_node) if is_min_node(current_node): return min(minimax(children_of(current_node))) if is_max_node(current_node): return...
  9. brochesspro

    Relative Velocity of a Passenger Hitting the Dashboard in a Car Crash

    Where exactly have I gone wrong? I think it is the part where I assume that the person gains the deceleration of the car, but I have no other way to proceed in this case. Also please only use the equations that I have posted below, and it would help if you would not use the equation for...
  10. Bhawna L

    Sketching a graph of contaminants after a train crash

    I tried to graph this equation, but all I am getting is a straight line that is x=0. I don't understand what I am doing wrong.
  11. J

    My destructor is causing my program to crash

    Below is my code. The include directives and the using std::* declarations have been removed for brevity: class HasPtr { friend void swap(HasPtr&, HasPtr&); public: HasPtr(const std::string &s = string()): ps(new string(s)), i(0) {} HasPtr(const string &s, const int &j) : ps(new...
  12. jk22

    World Economy Crash: Impact & Causes

    Suppose the world's economy crashes, this would mean : 1) it was not the whole world, since the Earth economy is a closed system, so the well going economy went somewhere else not known ? 2) there are extraterrestrial economies outside the solar system maybe ?
  13. B

    Is a Crash Inevitable Given the Conditions Described?

    1. I'm trying to calculate the time at which the crash does not happen (if possible, because I don't know the official solution. I assume the crash is preventable). At the time t the truck decelerates and makes the distance ##s_2= \frac{v_2^2}{2a}##. In the same time the car drives with the...
  14. Alfos001

    Seat-belt effects on passengers during a crash

    I have attempted solving this problem several times on an long since finished online quiz. However no answer I gave seemed to be correct despite what I could reasonably understand regarding the effect of seatbelts and their effect on reducing force by extending the distance of deceleration...
  15. L

    SSD crash after Windows 10 update on Lenovo Thinkpad X1 Carbon 5th Gen

    Hi all, I have a laptop Lenovo Thinkpad X1 Carbon 5th Gen (Intel(R) Core(TM) i7-7500U CPU @ 2.70GHz 2.90 GHz, 8 GB RAM). It was bought with Windows 10 OS installed on SSD 512 GB (model of the disk is SSDPEKKF512G7L). Since the 1st running, the laptop was constantly heating and fan made much...
  16. Greg Bernhardt

    News Ethiopian Airlines 737 crash discussion

    https://www.cnn.com/2019/03/10/africa/ethiopia-airline-crash-nairobi-intl/index.html There is now a lot of speculation about whether something is seriously wrong with the 737 MAX. https://www.cnn.com/2019/03/10/africa/ethiopian-airlines-crash-boeing-max-8-intl/index.html
  17. B

    Car Crash Analysis: Analyzing Friction & Speed

    Homework Statement Your consulting agency, with its extensive knowledge of physics, has been subpoenaed to provide expert testimony at an automobile accident case in civil court. The case involves a crash between a Ford Escort car and a tractor-trailer truck. 1. The police department...
  18. russ_watters

    Boeing Lion Air 737 Crash Investigation: Focus on AOA & Airspeed Indicators

    I've been following the Lion Air 737 crash investigation with interest. As is often the case, the media's extremely poor understanding of technical matters makes it a little difficult to follow. One article I raid proclaimed that "the black box" had been found, but the author apparently didn't...
  19. jim mcnamara

    Insect, arthropod, and insectivore population crash

    Popular science version: (Let me know if the link has problems) https://www.washingtonpost.com/science/2018/10/15/hyperalarming-study-shows-massive-insect-loss/?utm_term=.f9b8006df72b Long term sampling from the 1970's to 2017/2018 shows losses of insect, arthropod, and insectivore populations...
  20. L

    Was the Driver Speeding Before the Crash?

    Homework Statement "Based on the following data, determine if the driver who crashed was driving over the speed limit" The relevant data given is: -A 2002 Volvo t-bones a truck in an alley with a speed limit of 20km/h -An eyewitness heard tires screech, then a loud bang, and also said the...
  21. Kenneth Boon Faker

    Why do cars crash? (Instead of passing through each other)

    If everything is made of atoms, and if atoms have so much empty space inside them - and if the building blocks of atoms are made up of wave-like particles that aren't solid (strictly speaking) - then why do cars crash and billiard balls bounce off each other, as opposed to passing through each...
  22. G

    I Aviation safety plane crash question/idea

    So you know I've been wanting to ask this question for some time now. Everytime you hear about an aviation disaster it is usually a plane that has had some trouble either with technical stuff or less often due to pilot error or otherwise, but what I want to say with that is that a big commercial...
  23. D

    MATLAB Mastering Matlab: Graphing Functions Made Easy

    The MATLAB command plot plots points in a two-dimensional figure and connects them with straight line segments. So, here $y$ is a vector with $n$ entries $(1; y(1)); (2; y(2)); (3; y(3)); : : : ; (n; y(n)):$ So the MATLAB command is given below for an example: y = [1 -3 3 -4]; >> plot(y)...
  24. T

    How much sound in an airplane crash?

    I'm engaged in a discussion with a friend about how loud is the sound of an airplane crashing into the ground. I'm considering that the sound wave produced is roughly spheric. I need to know how much (percent) of the kinetic energy the airplane has before hitting the ground is converted into...
  25. deuce123

    I Particle accelerator question -- when the protons "crash" particles are created

    I'm not sure if this is the right place for this question., but I'll ask anyways. So in particle accelerators when the protons "crash" particles are created because of the extremely high amount of energy(example of e=mc^2?)? Is that correct? Also, where do these particles come from? The Higgs...
  26. M

    Why are my Mac apps crashing constantly?

    Hi PF! In the past 24 hours programs on my Macbook Pro have been incessantly crashing. I'm running OSX Yosemite 10.10.5 (I'm waiting to update until I update MATLAB so I can run it on Sierra). So far three programs have been crashing: MATLAB, Safari, and App Store. Any idea what to do? I've...
  27. D

    Solving the Car Crash Puzzle: Newtons 2nd Law

    I've been trying to study for my final and I can't seem to figure out how is this suppose to work. 1. Homework Statement A wall (m infinite, v=0) hits a car (m=2600 kg; v=142 km/h). The car becomes deformed and the crush zone (0.7 m) is compressed. Calculate the corresponding acceleration...
  28. A

    Car Crash Work and Energy Problem

    Homework Statement A red van came through and crashed into a green van. The driver of the red van claims that he was driving at a speed of 11 meters/second at the moment of the crash. You want to find out if his claim is true. a. the mass of the red van is 1000 kg b. the mass of the green van...
  29. UNCCME

    How are Flight Data Recorders built?

    I am curious as to the components of FDRs that allow them to sustain such g-forces and immense heat. Surely it's not just a steel box filled with paraffin wax. What alloys are used? what shapes are used in internal construction to prevent crushing/penetration? What do they insulate with and how...
  30. kyphysics

    How Did Goldman Sachs Make Money From 2008 Housing Crash?

    Here's what I understand (please feel free to correct me on anything if I'm wrong): i.) Goldman Sachs created MBSs (mortgage backed securities) with sub-prime mortgages that they bought. They essentially bought up a ton of these mortgages and packaged them all together into a giant...
  31. W

    B Calculate Force of Car Crash: Bill's Story

    Hi I am here asking for some help. I simply struggle with maths due to ahead injury sustained in a motor accident. I am trying to find out the forces that I suffered in the crash. I know from software forums people do not like doing other peoples homework, instead the goal is to help others...
  32. D

    A Why does my chosen basis set for W crash (DFT)?

    Hello, I am trying to optimize a molecule with the chemical formula C60H52O18P4S4W2. I have tried using different Basis Sets on my input file but I keep getting the following error: " Standard basis: Aug-CC-pV5Z (5D, 7F) Atomic number out of range in CCPV5Z. Error termination via Lnk1e in...
  33. J

    Equations for bending steel in a car crash?

    I wanted to know what formula's do I need to figure how much force is required to make a dent in a car. I am then placing a bumper guard made up of carbon fiber, and wanted to know what equation do I need to use to figure out how much force is required to make a dent with the carbon fiber bumper...
  34. A

    Establishing Speed in Motorcycle Accident: Seeking Help

    Hi I'm new to this forum and I might have putted this thread in wrong section. My question i would like to get answered its a bit complicated, I know... I have had very weird accident while riding a motorcycle as a courier in London. I don't know what caused the accident because I lost memory...
  35. bpcaddy

    Automotive Crash Test Software for VW Rabbit Car 1981

    For my senior project i plan on litening a vw rabbit car. 1981. Any software that i could uuse to model the care and provide great data on how i could improve the safety after i cut it up to lighten it? Thinking adding roll bars or something.
  36. Multiple_Authors

    Why Don’t Electrons Crash into the Nucleus in Atoms? - Comments

    Multiple_Authors submitted a new PF Insights post Why Don’t Electrons Crash into the Nucleus in Atoms? Continue reading the Original PF Insights Post.
  37. S

    MHB Solving the Probability of Crash for SUV Drivers

    I am trying to solve this task: The SUV drivers use their telephone four times as often as the drivers of other vehicles. At the same time, using your telephone while driving increases risk of an accident fourfold. Does that mean that the SUV drivers are 16 times more likely to have an accident...
  38. edguy99

    How many partons can you crash at once?

    Interesting article on double-parton collisions in Fermilab Today. https://www.fnal.gov/pub/today/archive/archive_2015/today15-11-12.html Do triple-parton collisions occur?
  39. N

    Stray Asteroid or Unknown Meteor? Meteor Crash in Thailand Captured on Dashcam!

    http://home.bt.com/news/world-news/dashcam-captures-meteor-lighting-up-the-sky-over-thailand-11364014422139
  40. H

    News Sinai plane crash -- Terrorists responsible?

    An airliner crashed in the Sinai peninsula in Egypt carrying 217 passengers (214 Russians and 3 Ukranians). All presumed dead. http://www.bbc.co.uk/news/world-middle-east-34689870 What a tragedy! My thoughts go to their families. ISIS affiliate in Egypt, the so-called Sinai Province, has...
  41. wolram

    News F-18 Jet Crash: US Marine Corps Pilot Dies in Ely, Cambridgeshire

    http://www.bbc.co.uk/news/uk-england-cambridgeshire-34593948 Thank you for your service. RIP. A US Marine Corps pilot has died in an F-18 jet crash, close to an RAF base. The jet came down on farmland in Redmere, near Ely, Cambridgeshire, with the alarm raised at 10:30 BST. The Hornet...
  42. G

    How Much Energy Does a Fire Truck Generate in a Crash?

    Hello all, I am in need of some help. I work for a fire department who had a significant fire truck crash last summer. Because of this, my department has set about making a training program for our drivers. Lucky me, I am in charge of said program. So I need some help. Here is the story. Last...
  43. G

    The Energy of a Fire Truck in crash

    Hello all, I am in need of some help. I work for a fire department who had a significant fire truck crash last summer. Because of this, my department has set about making a training program for our drivers. Lucky me, I am in charge of said program. So I need some help. Here is the story. Last...
  44. R

    Solving Car Crash Scenario: Find v1 of Car A

    Homework Statement Car A (m1=1405kg) crashes into Car B (m2=873kg) which is stationary and perpendicular to Car A. Car B is moved a distance of 1.8m out of the way and Car A rolls to a stop 9.6m away at 1.93 m/s. Assuming the coefficient of friction is 0.8, can the velocity of Car A be...
  45. H

    Car Crash Physics Project: Whiplash & Brain Injury Risk

    Okay so I have to do a project that examines whiplash and brain injury in physics. My scenario is a minivan full of 7 people of various masses. This van is at rest and gets struck from behind by a truck going 75 mph. What is a reasonable acceleration for the van after it gets struck? I'm trying...
  46. Astronuc

    News Germanwings 9525 Crash in French Alps

    I saw headlines and news yesterday. Very strange situation indeed - the plane was in a controlled dive, on it's flight path, for about 8 minutes. Why? Pilot in German Airbus crash was locked out of cockpit: New York Times...
  47. J

    Is the Dow Jones heading towards a crash?

    Let's think about this for a moment. The Dow has more than doubled over the past 5-6 years. If that were indicative of real economic growth, then it would mean that U.S. productive output has more than doubled over that time. Does anyone really believe we're producing over twice as much as we...
  48. marellasunny

    Front crash with crumple zone: relative velocity calculation

    EURONCAP front crash test involves crashing a car moving at 64 kph onto a deformable barrier at 40% of the total vehicle width. According to the EURONCAP website, this is equivalent to two vehicles crashing into each other at 55 kph. How did they arrive at this figure? I presumed that the...
  49. M

    How Do Crash Dummies Help Us Understand Car Safety Physics?

    Homework Statement a. A set of crash tests consists of running a test car moving at a speed of 11.2 m/s (25 mi/hr) into a solid wall. Strapped securely in an advanced seat belt system, a 57.0 kg (126lbs) dummy is found to move a distance of 0.750 m from the moment the car touches the wall to...
  50. B

    Crash Test Craig drives his 800kg car up a 100m ramp. Help?

    Homework Statement Crash Test Craig drives his 800kg car up a 100m ramp that is at an angle of 35 degrees above the horizontal. The car exerts a forward force of 12000N and the force of friction between the ramp and the car is 20N. He is trying to jump over a series of spinning helicopter...
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