# What is Explosion: Definition and 274 Discussions

An explosion is a rapid expansion in volume associated with an extremely vigorous outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Supersonic explosions created by high explosives are known as detonations and travel via shock waves. Subsonic explosions are created by low explosives through a slower combustion process known as deflagration.

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1. ### I What happens when an explosion occurs on the surface of the moon?

In an explosion in space, material is heated and expands. On the surface of Earth, it doesnt get too far, instead transferring its energy into shockwaves and tremors. But on the surface of the moon, if I'm right: - Explosions with slower initial speeds (of the expanding material that makes up...
2. ### Does the hydrogen bomb emit beta radiation?

Does the hydrogen bomb emit beta radiation when it explodes... according to the equation……n+Li6 (alpha+tritium) + deuterium( alpha+n) = 17.6 mev?
3. ### B What is the “Unknown physics” of the new Kilonovae explosion?

Scientists recently observed a kilonovae explosion. To their surprise, the explosion is completely spherical. They are saying that this is the cause of unknown physics but I don’t understand why they think unknown physics is causing this. What’s unknown about a perfect spherical explosion? My...
4. ### Explosion of 2 Carts on a Platform (Momentum)

My Explanation: This system is a closed system, so the center of mass velocity stays constant. It was initially at rest so the position of the center of mass is constant. After their collision, the 2 carts are to the right of x = 0. Center of mass originally was at x = 0, so the platform had to...
5. ### B Expansion of Space Itself, rather than due to an Explosion like the Big Bang?

Please explain how we know that it is space itself that is expanding rather than an expansion due to an explosion such as the big bang. In either case wouldn’t every object appear to be moving away from us? How do we determine that space/ time is expanding? Tex
6. ### B Conservation of Energy and Momentum in an Explosion

Hey, I have a question about explosions and how kinetic energy works during them. I have outlined my question on the attached image. Please let me know if something is wrong or needs clarifying. Thank you.
7. ### Bomb explosion -- calculating the momentum of one of the fragments

I think if the two parts move in -x and +y direction, it must be balanced by the resultant of the two vectors but in opposite direction. So ##p\sqrt5## will be the answer. But I don’t think this is the right way to solve this.
8. ### How much risk with first nuclear explosion test?

How sure were those involved with the first nuclear explosion test that there wouldn't be an unanticipated reaction of the explosion continuing beyond the material intended? I.e. that the Earth wouldn't go up in a ball of fire, the scientist's last utterance wouldn't be "Oops..."?
9. ### Expanding explosion from an Asteroid

An asteroid of mass M explodes into a spherical homogenous cloud in free space. Due to energy received by the explosion, the cloud expands and the expansion is spherically symmetric. At an instant, when the radius of the cloud is R, all of its particles on the surface are observed receding...
10. ### Conservation of momentum in an oblique launch and projectile explosion

This problem I already solved using another resource (just get the coordinate of the center of mass reach and from it, get to the larger mass. R = (3v02) / (4g)). But I'm having some trouble calculating using moment conservation. Here what I've done so far: $$3\vec v_0 = \vec v_1 +2\vec v_2$$...
11. ### Stargazing Will the supernova explosion of Betelgeuse influence the Earth?

Will the supernova explosion of Betelgeuse influence the Earth's climate and temperature or even the sun in any significant way?
12. ### How much energy would enter your pupils from an explosion in space?

The answer is 1.1 J, but I don't know how to get there. The only equation I can think of that might be related to this is Intensity, which I've added above. I could find area, using .0004m as the diameter, and energy using 2.0 E 46 J, but I get stuck on energy.
13. ### Explosion energy dissipation and Ek

Hello, I think the only energy involved is kinetic energy. So I subtract to get the difference between two stages to find the energy cost by explosion. (0.5*9.6*14.6^2)-(0.5*0.2*2.4^2)=1022.59J However the system said that this answer is wrong, So I wondered where did I make a mistake?
14. ### Mechanics: Explosion of an Object Vector Diagram

Well, I understand that according to the conservation of momentum the total momentum of a system is conserved for objects in an isolated system, that is the sum of total momenta before the collison is equal to the sum of momenta after the collision. In this case, the momentum of the object...
15. ### Foyle's War, The Hide - cause of explosion?

In the episode The Hide of the series Foyle's War, what causes the explosion in the Wainwright's guest house?
16. ### Maximum possible speed of explosion fragments

Let say the object explodes to three identical parts A, B, and C and initially the mass moves to the right before explosion. To obtain maximum possible speed (I assume C is the one with maximum speed), I imagine C should move to the right and A and B both should move to the left. Is this...

18. ### How to calculate the pressure of an explosion?

Say there's 2 grams of gasoline (vapor) (E85) and sufficient air, how can you calculate the force/pressure of the explosion when this mixture is ignited? The pressure of the mixture before ignition is 400 pascal. The calorific value of the fuel is 45 MJ/kg. The volume in which the explosion...
19. ### Explosion of 74HC14 IC in Old Stock

Recently i am trying to put in use a stock of old 74x series microchips manufactured around ~2000 AD. Unfortunately, one of microchips 74HC14 (hex schmitt trigger inverter) in SOIC-14 package have exploded in test setup in the moment the power was applied. Loud "popping" sound, flash of blue...
20. ### Possible to calculate the strength of a nuclear explosion from a photo?

Details of this calculation from the photo?
21. ### Ansys Explosion Simulation: Methane Gas Parameters

Hi everyone, I have a problem. I need doing simulation in AnSys about explosion methane (as gas), unfortunately program has not such material and I do not know explosion parameters of methane (8.5% in air). I am enclosing picture with parameter of TNT (AnSys has material TNT), and does someone...
22. ### Blast radius of mechanical explosion

Imagine a container with compressed air ruptures. Inside is a metric ton of air, just very dense. If it explodes, ignoring fragments of the container and the ground, how would i calculate the blast radius? Do I need the Volume of the container or the density? I thought it might just be the...
23. ### Chernobyl Did Chernobyl divers prevent a multi megaton explosion?

There appears to be much myth about the 'divers' that swam through radioactive water to drain the water underneath reactor 4 at Chernobyl. This History channel link alludes to some of the myth https://www.history.co.uk/article/the-real-story-of-the-chernobyl-divers. It also links to a youtube...
24. ### Tornado Biggest Lightning Thunder BOOM Explosion EVER

I was a storm chaser for many years. I have seen 100s of tornadoes. I have seen all types of lightning, hail, wind, rain, etc. I thought I had seen it all until last night. Radar shows counter clock wise rotation moving east I appeared to me in the exact path. There were no lightning...
25. ### Nuclear Explosion in Space… How would it work?

Did a quick search of an explosion in a vacuum and got most of what I was looking for, but on CBS Sunday morning they had a segment on restoring and reevaluating all of the immense footage of America's atmospheric nuclear testing program. They showed some amazing footage of the expansion of the...
26. ### Conservation of Momentum (Explosion Kinematics)

Homework Statement [/B] A 3200 kg space vehicle (including a launchable lifeboat) is traveling with a velocity of 300 m/s in a straight trajectory [East]. The lifeboat (200 kg) is fired at a speed of 1000 m/s [N of original trajectory]. a) After firing it is found that the horizontal...
27. ### I How did Fermi calculate the strength of first nuclear explosion?

Hi There is a story that Enrico Fermi calculated the intensity of the first nuclear test at Los Alamos from the distance moved by scraps of paper. Are there documented details of the calculation in any paper / book ? TIA
28. ### Change in the potential energy of a star after explosion

Homework Statement Homework EquationsThe Attempt at a Solution I think : the question means that almost all of the potential energy gets used into the explosion. If this is true then the potential energy gets reduced by ## \frac { GM^2} R ## or if the star just gets transformed into a...
29. ### B What would happen if you take a piece of a pulsar

Hi, what would happen if you took 1 cubic meter of matter from pulsar into empty space what would happen does the matter will expand since there is no more strong gravity does will it explode ? would like to know your answers
30. ### Calculate the vertical motion of a piece of debris from an explosion

< Mentor Note -- thread moved to HH from the technical physics forums (because of a forum issue), so no HH Template is shown > There was a huge explosion, one small piece of debris was launched upward at v=5.3 km/s. Calculate its maximum altitude. a) Develop an expression for the maximum...
31. ### M 6.3 Explosion - 22km ENE of Sungjibaegam, North Korea

A M 6.3 earthquake caused by an explosion in North Korea about an hour ago has been recorded this size of quake is most likely caused by a nuclear blast M 6.3 Explosion - 22km ENE of Sungjibaegam, North Korea Time: 2017-09-03 03:30:01 (UTC) Location: 41.343°N 129.036°E Depth: 0.0 km cheers Dave
32. K

### The Big Bang: Exploding the Myth of a Center in Space and Time

I am wondering, if the big bang was an explosion how can it be that all of the space and time was created simultaneous. Because an explosion have a center, but everywhere is the center of the universe.
33. ### How does a C4 explosion work on a molecular level

I understand the fact that the detonator begins the reaction. The reaction happens many times release a ton of energy which causes the gases around it to rapidly expand and accelerate away (not the best summary). However, what causes the combustion which tends to happen as a consequence of the...
34. ### Splitting/Exploding object & Momentum

Hi, Homework Statement A free falling object of mass "m" falling from some height, collides the floor in speed of 20 m/s (perfectly elastic collision). In his 1/2 height back up he splits into 2 pieces- ¼m which going downward and ¾m keeping upward. The ¼m reaching the floor after ½ second. 1)...
35. ### Explosion and conservation of momentum problem

Note: Please only give hints please! No answers because I want the satisfaction of solving it. 1. Homework Statement A mass M at height h above flat round and falling vertically with velocity v breaks up explosively into 2 parts. The kinetic energy given to the system in the explosion is E...
36. ### I Why Does Fire Not Travel Backwards in a Gas Hose During Ignition?

Hi , a simple question arose in my head , why is that every time I have seen a hose attached to a gas tank being set on fire the fire always burns out of the end of he hose but the fire never travels backwards inside the hose back to the tank to explode it. the same I suppose happens to a...
37. ### Projectile Motion/ Explosion Mid air

Homework Statement So in the problem there is a projectile that is in the air and has no forces acting up, only the -9.8 acceleration down, the projectile is at the maximum height of say 10m and at this height (with a horizontal acceleration of around 40 m/s) explodes into two even 20g pieces...
38. ### Finding Angle and Intensity of Split Rocket at Maximum Height

Homework Statement A rocket is fired from from the ground at initial velocity of ##v_0## and at an angle ##\theta##. At its highest height it splits into 2 parts of equal masses. The first part is fired straight up and at velocity ##v_0/2##. Find the angle and intensity of the second part...
39. ### Finding velocity of a piece after explosion

Homework Statement A firework of mass 1 kg is placed on the ground and ignited , the impulse created by the explosion causes it to move vertically upwards,after 4 seconds a second explosion takes place in air and the horizontal impulse forces cause it to separate into 4 identical pieces 2...
40. ### News Explosion in NYC: No Casualties Reported

There has been an explosion in NYC. Thankfully, it appears no one has been killed. http://edition.cnn.com/2016/09/17/us/new-york-explosion/
41. ### SpaceX Investigating the SpaceX Rocket Explosion of September 1, 2016

As already posted on PF, and you have likely seen in the news, a SpaceX rocket exploded, September 1, 2016. Elon Musk is reaching out for help in finding out how it happened. http://www.csmonitor.com/Science/2016/0911/SpaceX-needs-you-Musk-calls-on-public-government-in-explosion-probe I took...
42. ### Find Total Force of Explosion in Asteroid Mine Shaft

How would I find the total force of an explosion if I have the energy of the explosion, and no displacement? The explosion is taking in place inside a mine shaft in an asteroid, and I need to know if the asteroid would blow up or not? Is it possible to find the force, and how would I do it?
43. ### Calculating Velocity of Falling Grenade Fragments: Momentum Equation Solution

Homework Statement A grenade is falling from the height 19.6m .Finding velocity of both masses(fragments), if m1 is equal to 2 times of m2 Homework Equations Conservation of Momentum v2 = u2 + 2as The Attempt at a Solution I think this is a pure mathematic problem :/ I can cut the mass out...

45. ### B Nuclear Explosion Legs - What are They?

I always wanted to ask a nuclear scientist about this. What are these weird wiggly thin lines we always see during a nuclear bomb detonation? If you look to the right side of the screen on the first video, they look like the "legs" of a fine whisky dribbling down a fine whisky glass. But what...
46. ### Did the 1883 Krakatoa Explosion Leave Ships in Peril?

On route to China, the Irish merchant vessel Charles Bal ran with the wind, NW through the Sunda Strait, just prior to the explosion of Krakatoa on 27 August 1883. [My comments]. The following report is extracted from pages 253 to 259 of: “The Log of The Cutty Sark”. Basil Lubbock. 1925. It is...
47. ### B If there is explosion with absence of oxygen?

According to Dr. M. Kaku, how a big bang theory supports when there was an absence of oxygen in the outer space?
48. ### Finding Work of a Hydrogen Explosion

Hello, I'm curious to find how much work is released by hydrogen explosion. My method is by making a projectile launched vertically by hydrogen's explosion. Take the highest peak that the projectile launched, multiply it by the projectile's mass and gravity which should yield the maximum...
49. ### Help with nuclear explosion released isotopes

After a nuclear explosion in the environment remains a lot of half-life of a radioactive isotope . Which of them pose the greatest danger to people , find themselves in the same place after a certain time ? why?
50. ### Did an explosion of a Black Hole make the Big Bang

I'm not talking about white holes. Indeed, the big bang as the explosion of a black hole are an explosion of singularity.