Shock Definition and 221 Threads

Was reading a crane-operations manual and it had a Section on what to do if your boom accidentally contacted overhead electrical wires. It advised not trying to step out of the cab (of course); but in case of imminent danger advised jumping out (makes sense). The interesting part came after...

I'm just trying to get a better grasp on sound waves and shock waves. Let's say I have a cylindrical rod of length L with no forces acting on it, and I push on the back of it with some constant velocity less than the speed of sound, c, of the material the rod is made of. Will the front of the...

The example I have in mind is when a pole vaulter's pole breaks. I remember at last year's Olympics one of the commentators made a commenf about thw shock waves thag would've been traveling through the pole and the guy's hands when it broke. I did a search and it was mentioned in some...

Homework Statement Suppose that a blast wave, which might have been initiated by an atomic bomb explosion, is traveling through air at standard atmospheric conditions with a speed of 60,000 m/s find change in ( pressure , temperature , stagnation pressure , velocity ) produced by the wave...

Hello, I'm trying to estimate how long the impact of a steel ball hitting a plastic box would be. The actual case: you drop a steal ball d=0.51mm, m=0.54kg from h=0.74m onto a box made of plastic, the impact speed is 3.86m/s and force 4J. I want to know the deceleration speed during impact...

In low pressure gases, speed of sound is independent on pressure and depends only on temperature. Therefore increase of pressure will propagate as shockwave - front of the wave compresses and heats the gas, allowing the rear of the wave to travel faster and pile up into a shock. By the...

in welding operation , you never hit by electric shock,why?

What are the differences (I'm really trying to understand the differences in the context of an explosion). When you hear it, are you hearing all 4 waves? Which waves cause the damage and why - why not the others? Also, when NASA launches the space shuttle, they release water to absorb the...

An hydraulic shock absorber of a vehicle operates, usually, by viscous friction: the braking force is proportional to the relative speed of the mechanical parts (piston sliding in cylinder) through passage of the fluid (oil); in some more sophisticated cases there are valves that reduces the...

Suppose traffic is moving uniformly with a constant density $\rho_0$ when a traffic light turns red. At time $t = 0^+$, the initial density profile is then modeled according to the figure below. The resulting wave motion of the disturbance is governed by $$ \frac{\partial\rho}{\partial t} +...

I have to do some dataacquisition from a car with some accelerometers. 4 accelerometers is placed on the wheels before the shock absorber. And i need to calculate the maximum applied G-force on the accelerometers. Just an approximately value, not taking in account the type of wheel...

I am trying to show how the shock wave angle varies as I hold the deflection angle constant and increase the Mach number. I am trying to solve for Beta (shock wave angle) using the theta-beta-mach relation: tan(θ)= 2cot(β) * (M2sin2(β)-1) / (M2(1.4+cos(2β))+2) This seems like it should be...

If an object of VERY high mass were to hit a hypothetical wall at a high velocity and the wall somehow withstood that, what would happen to you if you were standing on the other side close to the wall but not touching it? Would there be some sort of wave transmitted through it? If so, would this...

Hello, I am new here so I apologize in advance if my question is not formatted as it should. I have an application where a large pressurized vessel is releasing part of its contents (gaseous) into an "empty" container (air), much smaller, that is at atmospheric pressure. I need to know if the...

Hello experts. This is a unusual behaviour. I moved to new house, an apartment newly constructed less than a year old. I first noticed shock when I was disammbling my computer , i immediately took out multimeter and tester. First checked with tester, it did not show any symptoms of...

"New results from NASA's Interstellar Boundary Explorer (IBEX) reveal that the bow shock, widely accepted by researchers to precede the heliosphere as it plows through tenuous gas and dust from the galaxy, does not exist." - Maria Martinez, SwRI Roadrunner, June 2012 So Voyager must actually...

Hi I have a few questions regarding gas dynamics... 1. when M=1, dA=0...what does this mean? Does it imply that if we have a converging (subsonic) nozzle with its exit mach no,say 0.8, and then direct the flow to a constant area tube, then we have to attain M=1? 2. When we know the length...

My laptop is equipped with hard drive shock protection. If I am watching a movie and the accelerometer senses a perturbation (me shaking the computer) the image is immediately frozen, but there is no interruption in the sound. Why is this the case?

Homework Statement Anyone know of any experiments I can do show demonstrate a shock wave or supersonics flow ? The Attempt at a Solution Closest thing I can think of is whipping a whip, because the end moves supersonic

Hi, I need to know how much shock is needed to detonate a C4 plastic explosive for my report in chemistry. I searched for it, but I didnt find a certain number. Somewhere I read it's about 4900 m/s of detonation velocity needed to create the shock, but it was from a source I wouldn't trust...

Hi all, i get shock when i touch any of my electronic equipments (washing machine etc). To avoid shock i need to remove the connection from the socket and then only i can do maintenance and put the connection back to the socket and operate. Obviously i think earthing is the problem before i...

【HELP】Equation of temperature increase by shock wave Hi there! What is the equation of the temperature increase when the ideal gas swept by a planar shock wave (Mach number, M)? Thank you!

Hi guys and gals, with respect to SNRs (or anything for that matter) What is the difference between a shock wave and a blast wave? Is it just that a blast wave is a sharp peak in the change in variables, where as a shock wave has a region behind it in which the variables gradually...

Homework Statement What is the spring constant of a spring in a shock absorber? Also, does a spring constant of 288 N/m sound right for a regular spring such as the one attached?

I have always been under the impression that the "Live" conductor was the most dangerous conductor. The Live carries 120V (US) 240V (UK) and the Neutral carries 0V, but yet it is still possible to get an electric shock from a Neutral :confused: Why is this possible? Is it because it is...

So I know what a shock wave is but what's a shock ? is it just the front of the shock wave ?

1) How does an explosion or impact (e.g. meteorite) create a pressure wave? In the case of a meteor, if kinetic energy is being transferred into the wave, how does this conversion take place? 2) Is it the shock wave from an explosion or impact (e.g. meteorite) just the collision of air...

I am trying to design a bicycle cargo rack that uses shock absorbers to protect sensitive equipment (i.e. a laptop computer). I have data for the maximum height from which laptops can fall without damage as well as the maximum acceleration to which they may safely be subjected. I am planning to...

Is it possible to use a solenoid as a shock absorber? i.e run current through the solenoid, producing a magnetic field opposing a separate magnet attached to whatever it is receiving the shock impulse, thus dampening the effect according to the amount of current input.

Suppose you have a 1cm diameter heat source suspended 2m above the ground. How many watts of heat energy does it need to expend to create a shock wave?

I've just viewed the National Geographic Channel's "Engineering Connections" program. specifically, the episode entitled "Airbus380", and that episode's discussion of the A380's landing gear shock absorbers, which used bicycle pumps filled with water to illustrate the basic principle of...

As part of an assignment I have to redisign a product using an eco-material. I choose phone covers. From the silicone, rubber or plastic ones I intend to redisign using bamboo or cork. I would like to have some insight on the matter, what are the main properties i should be looking for...

why do we get SHOCK if we touch current?? when current pass through our body we get feeling of shock., why it happen?? person may turn black or die if exposed to high volt shock for long time?? why it hapens?:rolleyes:

Dear Friends and Senior Members , I am from India, Asia and we have the 240 V electrical system. We also have Geyser / Water Heater installed in our home 2 Nos. From the past 2 months I observe that sometimes, really sometimes the water heater installed in my room gives shock, I mean the...

Hello Everyone, If you are grounded and touch an electric fence that is at 10,000V, say, you will experience a shock. What happens if you were to jump in the air when touching the fence? Would you still feel a shock? I'm getting confused because even in the air, your body is still at the...

so i have learned that potential difference always occurs between points which have some common node that is if you have two circuits which don't have anything in common there will not exist any potential difference between any two points my question is why do we get electric shock when we touch...

Homework Statement When a box of unknown mass is placed into a trunk of a car, both rear shocks are compressed a distance of 7.00cm. If we assume the two rear shocks are made from springs, each with a spring constant of 35,000.00N/m, what is the mass of the box? (Assume g = 9.80m/s2)...

I'm trying to wrap my head around shock waves produced by bullets and their properties. In particular I'm interested in what affects the duration of the shock wave in time. Say someone shoots at me, the bullet passes near me, and I hear the shock wave produced by the bullet. If you look...

Say you touch the hot wire and a piece of plumbing simultaneously. Then current flows through the hot wire, through you, to the ground, and I assume (though I'm not sure) to where the ground wire is tied to the neutral wire (at the breaker panel). But is the current in the ground mainly through...

Which shock will be most dangerous for human 1.High Voltage and low current or 2.High current and low voltage

Hello, I was wondering what was the effect of a normal shock wave on the physical properties of a fluid. How does the entropy (and perhaps pressure, temperature and density) vary from upstream to downstream of a normal shock wave? Thanks for your help.

A friend of mine grabbed a handheld 10,000 volt tesla coil (the metal end) in one hand and a florescent bulb-tube thing in the other, and showed me that he could light the florescent tube using the electricity from the tesla coil. My question is, why did it not shock him, and are there any...

During spinal shock, are all spinal reflexes gone, or only reflexes below the lesion. Thanks :smile:

I was reading about current electricity and some how I came across the idea that a circuit of no earthed point will not cause any electric shock. I wonder if it is right cause if it is, why do we need an Earth wire in our appliance. I am also suspicious because if the circuit is not earthed...

Amount of current and voltage in an average "shock" from a door nob? What is the amount of current and voltage in an average "shock" from a door nob/handle? I have looked everywhere and cannot seem to find it! Please help! Thanks

Hello everyone, Quick question about spinal cord shock. 1. If C7 is transected, why does heart lose its sympathetic supply. I don't know much about autonomic nervous system, but isn't it coming from sympathetic trunk located outside the spinal cord, so how can it have an effect. 2. Also...

Here's the problem : Air flows in a passage with an initial Mach No. 2. Determine maximum turning angle A for which 3 regular reflections (i.e. no Mach reflection) of the original oblique shock are possible? Now, what exactly is a mach reflection? Also, what is the minimum Mach number...

Hi all, I am a student designing a camera fixture for my senior design project. We are halfway through our project right now and we are trying to do some validation stuff for our fixture. One of the requirements for our fixture is for it to withstand 6 g's of shock during...

If I drop a box of the side of a building (20m) that is 5kg, what is the G shock that this will experience? F=mg is the force, obviously. Based on basics, I'm coming up with 1G, but that doesn't make sense - the shock is going to be bigger based on the height. Say I determine the energy...

In my attempt to obliterate my ignorance I'd like to discuss something related to the recent news story about a young man who attached two clamps to his nipples and then had a friend plug it into a wall socket. http://news.gather.com/viewArticle.action?articleId=281474978486647" <-- News Story...