What is Shockwave: Definition and 32 Discussions

In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium.For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference.
Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance.
When a shock wave passes through matter, energy is preserved but entropy increases. This change in the matter's properties manifests itself as a decrease in the energy which can be extracted as work, and as a drag force on supersonic objects; shock waves are strongly irreversible processes.

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  1. KataruZ98

    Kinetic energy transfer from shockwave to secondary body

    I would guess that by multiplying the pressure exerted by the shockwave on the body, and then the resulting force - here ~69 Newtons - per the distance the shockwave passed through when traversing body A, I could get the work done but I’m not sure if it’s that easy and whether or not I should...
  2. Borek

    I Second Tonga shockwave - why a drop in the pressure?

    I already posted this image in GD as a curiosity, but there is one thing that I don't get. This is pressure recorded by my weather station near Warsaw in Poland after the Tonga eruption (the description says '24 h' but it is wrong, I forgot to modify the script generating the plot). Around 20:05...
  3. Borek

    Tonga eruption shockwave and weather station(s) in Poland

    Warsaw times, subtract 1 hour for GMT. It was pointed to me yesterday that we should see these by the same guy that sends helium filled balloons around the world (his latest is in the air for about half a year now), I posted about him some time ago. He posted an image from his weather station...
  4. C

    I How do shockwaves in a 1D linear lattice work?

    I am struggling to understand shocks in a one dimensional lattice with a linear spring connecting the masses. Say I have a one dimensional lattice with a linear spring constant, k and lattice spacing a. If the particles in the lattice has mass, m then my speed of sound c is a*sqrt(k/m). That is...
  5. J

    I How do waves following a shockwave catch up to the shock wave?

    I was in an argument about a jet engine and I was arguing that since there is a cutoff in terminology what would kill someone approaching a engine is not technically sound, but a shock wave, (I'm probably wrong about this, but that's not the question). That got me wondering how waves can catch...
  6. Spinnor

    NASA NASA Captures First Air-to-Air Images of Supersonic Shockwave

    https://www.nasa.gov/centers/armstrong/features/supersonic-shockwave-interaction.html “We never dreamt that it would be this clear, this beautiful.” Physical Scientist J.T. Heineck of NASA’s Ames Research Center in Mountain View, California gets his first glimpse at a set of long-awaited...
  7. D

    Shockwave of mushroom cloud rising at supersonic speed

    I'm modelling the Hiroshima nuclear explosion on a real time real scale physics simulator. My initial simulations based on data accumulated from wikipedia such as temperature of the fireball the radius of it and using air pressure and air density data based on the detonation height of 600m has...
  8. P

    How does the solar wind affect Earth's atmosphere?

    In the past many of us have read Mr Faraday calculated the “weight” of photon’s striking the surface of the Earth per acre at something like 4 and ½ ounces. Today, frequently we hear stories on the subject of the Sun's solar wind and how it is tearing away the Martian atmosphere and even...
  9. J

    Interaction of light with a shockwave

    Hello, I am trying to understand how light would interact with a shockwave, but for that I need to make sure my understanding of the physics of light is correct. It is my understanding that light travels independent of a medium because of the electromagnetic waves it produces. A wave, such...
  10. nicholas0211510

    Shock Wave Questions: Calculating Speed & Intensity

    How would one calculate the speed of a shock wave or intensity? For example, let's say something with a mass of 10 kg, with a velocity of 1000 m/s, travling in a straight line ,in Earth's atmosphere, at sea level . what formulas would one use to figure this out? Thanks in advanced
  11. 8eou8elisi

    Supersonic Flow Before and After the Shockwave

    After a Compression (Oblique) Shockwave during supersonic flight, the air speed (Mach number) is always reduced. I was wondering if an aerodynamic shape could be created to increase the speed of the affected stream to a Mach number greater than the freestream Mach number. I am looking for an...
  12. Physics Monkey

    Electric Field in Gravitational Shockwave Geometry?

    Hi all, I'm interested in the behavior of electric fields in a gravitational shockwave geometry. I'm specifically thinking about gravitational shockwaves due to null shells as discussed, for example, in Dray-'tHooft http://www.sciencedirect.com/science/article/pii/0550321385905255 (available...
  13. kelvin490

    How can shock waves travel faster than sound?

    Shock wave is caused by the disturbance of air by the airplane. When it propagate the mechanism should be the same as that of longitudinal sound wave. Why sometimes it can travel faster than sound? (also see: http://physics.info/shock/ )
  14. Newb_Aero_Ninja

    Convergent Subsonic Ramjet Utilizing Shockwave Compression

    Hi, I am working on investigating an idea I proposed regarding a ramjet that operates in subsonic flow (of a fixed speed) with a convergent intake. That utilizes the pressure immediately behind a standing shock-wave for compression. I have posted a link to my initial report here and I now need...
  15. T

    Chelyabinsk Meteor Shockwave 2/15/2013

    Was today's Chelyabinsk meteor destruction from an accelerated, focused "superboom" or a sonic boom? I assume it was not an explosion boom. I am trying to understand if the boom destruction radiated from central point or traveled with the meteor as an aircraft's sonic boom continually travels...
  16. P

    Traffic Shockwave Physics Topic

    1. Homework Statement : An abrupt slowdown in concentrated traffic can travel as a pulse, termed a shock wave, along the line of cars, either downstream (in the traffic direction) or upstream, or it can be stationary. figure below shows a uniformly spaced line of cars moving at speed v = 26.0...
  17. K

    Supernova Shockwave: Finite or Energy?

    I was wondering if a shockwave from a supernova is finite or reacts as energy and dissipates over distance. The reason I'm asking is because I'm wondering if a supernova could give solarsystems, planets and basically anything with matter a nudge. Then could the objects in space act like a...
  18. R

    Temperature ratio across normal shockwave

    Homework Statement Consider a stationary normal shock wave in pure diatomic nitrogen. The velocity and temperature upstream are known. Calculate the temperature ratio across the shock, assuming local thermodynamic equilibrium. Neglect any chemical reactions and electronic energy...
  19. A

    Shockwave Question: Solving Mach 3 Plane 20Km Above Person

    Homework Statement A supersonic jet traveling at Mach 3.00 at an altitude of 20 000 m is directly over a person at time t ϭ 0, as in Figure P17.43. (a) How long will it be before the person encounters the shock wave? (b) Where will the plane be when it is finally heard? (Assume that the...
  20. T

    Is This a Shockwave? - Physics Forums

    Hi all, Long time reader of Physics Forums but first time posting. Anyway, I work for a national magazine, and we are running an article on "Shockwaves". For the picture in the article we are using the attached image (or link here http://commons.wikimedia.org/wiki/File:Uss_iowa_bb-61_pr.jpg)...
  21. P

    Shockwave cosmology and white holes

    Now I’ve been trying to read up on this Shockwave cosmology model and wanted to see if I have the correct view since most of the math is over my head. Now from what I understand in this model is that there is a white hole singularity that explodes and instantly disappears and it produces a...
  22. R

    Solving for the Shockwave angle

    I'm working on this calculation project and I need to solve for quantities at various stages of the system. I'm having difficulty in solving for the shock wave angle. I came across this pdf which explains everything that I'm attempting to do. It has the equation I need on page 2 eq. (3.1) The...
  23. F

    How Can You Create and Control a Shockwave Using Electricity?

    How do u reproduce an maintain a shockwave without the use of explosives. Having an unlimited supply of electricity ie. straight from a reactor. Controlling the distance the wave travels ie. 100m
  24. R

    Power density and shockwave velocity limit in large explosions.

    A larger yield explosion has more energy, and presumably more power. However, is there a point where the power and power density drop of to become constant, and is this also the same with windspeed velocities generated? Let's say you had an asteroid, which hit the Earth with an energy equal...
  25. J

    Calculate the mach number after an oblique shockwave

    I am trying to calculate the mach number after an oblique shockwave. The freestream mach number is 2.0 and the angle theta is 25 deg. But on the Theta-Beta-Mach Diagram the line Theta=25deg does not intersect the Mach=2 line. So this means that the angle has exceeded the maximum allowable theta...
  26. V

    Distance for Nuclear Shockwave to Destroy a House

    Shockwave destroying a house [Solved] Homework Statement A 1-megaton nuclear explosion produces a shock wave whose amplitude, measured as excess air pressure above normal atmospheric pressure, is 1.4x10^5 Pa at a distance of 1.3km from the explosion. An excess pressure of 3.5x10^4 Pa will...
  27. D

    Would the removal of the sun result in a shockwave?

    Hello everyone, good day, So I understand that gravity travels at the speed of light and such. So naturally, if the Sun were suddenly gone, it'd take ~8 minutes for us to fly off and die. But I was reading Michio Kaku's "Parallel Worlds" and he used the trampoline/bowling ball analogy for...
  28. A

    What is the force of a shockwave expanding 100 fps in fluid

    I posted a few days ago . . . I think the point of my question has been missed. It was generally about ballistics. I elected not to go into any specifics because this is a physics forum not the FiringLine forum. So, I will specify and simplify . . . Here is my question. If a sphere is...
  29. D

    Calculating Plane Speed from Shockwave

    1. Homework Statement A plane passes from 900 meters over my head. I hear the shockwave after 2.2 seconds. At what speed in Mach is the plane flying ? Speed of sound = 331. 4 m/s 2. Homework Equations Machs = speed of plane / speed of sound 3. The Attempt at a Solution I don't...
  30. D

    Plane Speed: Calculating Mach with Shockwave Delay

    Homework Statement A plane passes from 900 meters over my head. I hear the shockwave after 2.2 seconds. At what speed in Mach is the plane flying ? Speed of sound = 331. 4 m/s Homework Equations Machs = speed of plane / speed of sound The Attempt at a Solution I don't have any clue where...
  31. 1

    Death by Shockwave: Effects of Naval Cannons in 1800s

    I'm not in the medical field and it has been a long time since my college physics courses so I turn to you folks for a possible answer and further explanation. It has been brought up on another forum concerning naval battles in the age of sail about the phenomena of sailors being killed or...
  32. F

    Getting Shockwave & Flash Plugins to Work in Firefox on XP

    I am pretty new to Firefox, but I am pretty much hooked. I do have one issue...I can't seem to get the shockwave or flash player plugins to work with it. I try using the plugin finder service, but it just hangs up. I have manually DL'd it and works fine on my IE, but still nothing with Firefox...