How do pendulums assist in earthquake damage reduction?
402767
In engineering terms pendulums are called mass dampers, usually either active mass dampers or passive/tuned mass dampers.  Check out the Earthquake Engineering Research Institute to start.
256787
yes they can and there is a device that is able to detect them, the only thing is that the device has to be over the area that is about to have an earthquake but seeing as they're expensive and there is only a handful of them in the world they dont do any good
813345
While at a gem and mineral show, My wife walked over to a table that had stands or displays of many different types of pendulums, she held her hand just away from each one as she moved down the line. There wasn't a draft in the arena yet one moved towards her. She felt this pendulum was calling out to her. After buying it and taking it home she sat down and braced her elbow on the table. She held the pendulums chain between her index finger and middle finger. Suspending it over the table.\nFirst she asked "could I have a yes?" the pendulum swung forwards and back. Then my wife asked, "could I have a no?" this time the pendulum swung from side to side. As my wife went through some questions, later we learn the pendulum was a female.\nmumbo jumbo?.. I didn't believe it, until I had seen it myself. The main thing I watched, was if my wife's arm was moving... It didn't.\nThis was our first time using a pendulum. Afterwards we spoke to others who have pendulums themselves. They told us how to clean, and care for them. As a "Rock Hound" I was willing to cut and craft these stones and minerals for my wife's hobby. This was about two years ago. Today we have a vast collection of stones, crystals, gems, and minerals...and yes a few more pendulums.
1070241
A seismograph measures the strength and direction of earthquake waves. It records the tremors and compares their strengths on the Richter scale. A scale of one is a minor earthquake, while a scale of seven is severe.
574466
A heavy pendulum with a ballpoint
375701
Try those...\n\nhttp://www.superbase.com/sb_scientific_current/example_pendulum.htm\n\nhttp://www.8886.co.uk/pendex1.htm
945993
Earthquake, shaking of the Earth’s surface caused by rapid movement of the Earth’s rocky outer layer. Earthquakes occur when energy stored within the Earth, usually in the form of strain in rocks, suddenly releases. This energy is transmitted to the surface of the Earth by earthquake waves. The study of earthquakes and the waves they create is called seismology (from the Greek seismos, “to shake”). Scientists who study earthquakes are called seismologists.\n\nThe destruction an earthquake causes depends on its magnitude and duration, or the amount of shaking that occurs. A structure’s design and the materials used in its construction also affect the amount of damage the structure incurs. Earthquakes vary from small, imperceptible shaking to large shocks felt over thousands of kilometers. Earthquakes can deform the ground, make buildings and other structures collapse, and create tsunamis (large sea waves). Lives may be lost in the resulting destruction.\n\nEarthquakes, or seismic tremors, occur at a rate of several hundred per day around the world. A worldwide network of seismographs (machines that record movements of the Earth) detects about 1 million small earthquakes per year. Very large earthquakes, such as the 1964 Alaskan earthquake, which caused millions of dollars in damage, occur worldwide once every few years. Moderate earthquakes, such as the 1989 tremor in Loma Prieta, California, and the 1995 tremor in Kōbe, Japan, occur about 20 times a year. Moderate earthquakes also cause millions of dollars in damage and can harm many people.\n\nIn the last 500 years, several million people have been killed by earthquakes around the world, including over 240,000 in the 1976 T’ang-Shan, China, earthquake. Worldwide, earthquakes have also caused severe property and structural damage. Adequate precautions, such as education, emergency planning, and constructing stronger, more flexible, safely designed structures, can limit the loss of life and decrease the damage caused by earthquakes.
610689
If x is +ve then a is -ve!!!Satisfy yourself with the equation.\nThe equation means that the acceleration is proportional to the displacement but in opposite direction.\nConsider a simple pendulum.When it is at the extreme position it has maximum tendency to go back to the mean position.That tendency is the restoring force which acts opposite to the displacement and exhibits itself as acceleration.If the pendulum is displaced to half the extreme position the tendency to come back is less.Thus the acceleration is proportional to the displacement but acts in the opposite direction.\nThe equation is true in all its sense.
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hehehehehehe first of all i wud like to say u tht ther is no advantage of earthquakes, everything are disadvantages ok\n\nso as u say u need for your project then i shall surely help but if its the best one (and i know it will be) please give me the best answer ok.\n\nThe disadvantages or the effects of earthquakes are as follows : -\n\n1.GROUND SHAKING : - \nGround shaking is a term used to describe the vibration of the ground during an earthquake. Ground shaking is caused by body waves and surface waves. As a generalization, the severity of ground shaking increases as magnitude increases and decreases as distance from the causative fault increases. Although the physics of seismic waves is complex, ground shaking can be explained in terms of body waves, compressional, or P, and shear, or S, and surface waves, Rayleigh and Love. \n\nP waves propagate through the Earth with a speed of about 15,000 miles per hour and are the first waves to cause vibration of a building. S waves arrive next and cause a structure to vibrate from side to side. They are the most damaging waves, because buildings are more easily damaged from horizontal motion than from vertical motion. The P and S waves mainly cause high-frequency vibrations; whereas, Rayleigh waves and Love waves, which arrive last, mainly cause low-frequency vibrations. Body and surface waves cause the ground, and consequently a building, to vibrate in a complex manner. The objective of earthquake-resistant design is to construct a building so that it can withstand the ground shaking caused by body and surface waves.\n\nIn land-use zoning and earthquake-resistant design, knowledge of the amplitude, frequency composition, and the time duration of ground shaking is needed. These quantities can be determined from empirical (observed) data correlating them with the magnitude and the distribution of Modified Mercalli intensity of the earthquake, distance of the building from the causative fault, and the physical properties of the soil and rock underlying the building. The subjective numerical value of the Modified Mercalli Intensity Scale indicates the effects of ground shaking on man, buildings, and the surface of the Earth.\n\nWhen a fault ruptures, seismic waves are propagated in all directions, causing the ground to vibrate at frequencies ranging from about 0.1 to 30 Hertz. Buildings vibrate as a consequence of the ground shaking; damage takes place if the building cannot withstand these vibrations. Compressional waves and shear waves mainly cause high-frequency (greater than 1 Hertz) vibrations which are more efficient than low-frequency waves in causing low buildings to vibrate. Rayleigh and Love waves mainly cause low-frequency vibrations which are more efficient than high-frequency waves in causing tall buildings to vibrate. Because amplitudes of low-frequency vibrations decay less rapidly than high-frequency vibrations as distance from the fault increases, tall buildings located at relatively great distances (60 miles) from a fault are sometimes damaged.\n\n\n2.SURFACE FAULTING : - Surface faulting -- the differential movement of the two sides of a fracture at the Earth's surface-- is of three general types: strike-slip, normal, and reverse (or thrust). Combinations of the strike-slip type and the other two types of faulting can be found. Although displacements of these kinds can result from landslides and other shallow processes, surface faulting, as the term is used here, applies to differential movements caused by deep-seated forces in the Earth, the slow movement of sedimentary deposits toward the Gulf of Mexico, and faulting associated with salt domes.\n\n\nDeath and injuries from surface faulting are very unlikely, but casualties can occur indirectly through fault damage to structures.\n\nSurface faulting, in the case of a strike-slip fault, generally affects a long narrow zone whose total area is small compared with the total area affected by ground shaking. Neverthe
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P waves are called primary waves...they do minor damage...S waves are secondary, they do slightly greater damage...the 'L' waves in an earthquake do the most damage, as they cause a 'rolling' effect radiating from the epicenter of the quake
1090548
Same as my previous answer except that a cantilever deals with negative moment although it makes no difference.  For hollow sections with the same Area as a I or solid rectangle would have much higher inertia because all of their mass is as far as possible from the centroid making for a very high EI and a very low deflection
403112
use swinging field dynamo meter/ reaction principle.
841696
A ring beam ties together the walls of masonry or adobe construction for added earthquake resistance. It is typically made of wood or reinforced concrete and laid along the tops of the walls, and provides tensile strength that masonry lacks, especially at the joints between walls.
423229
Go to this site http://www.bksv.com/pdf/Measuring_Vibration.pdf it should help you out with your question.
863216
It has to do more with the material of the ground rather than with the surface. It all depends on it's elastic coeficient. The least elastic, the more it will bounce because of the transmission of the kinetic energy.
792458
I'm assuming the amplitude is the horizontal distance from vertical.  In that case, the amplitude is the base and the pendulum length is the hypotenuse of a right triangle.  Figure that vertical side, subtract it from the length of the pendulum and that's the vertical distance it falls through.  Energy is the weight multiplied by this distance.
852108
Here's an answer that comes from a class I took in structural engineering.  Every building has a natural resonant frequency, ie, a frequency that it tends to oscillate at if it's shaken.  It's just like a tuning fork, or the string of a violin.  If an earthquake shakes the structure at a rate equal to its resonance, it will vibrate much more intensely, and be subject to more damage, that would be the case if the frequency were different. Also, I should point out, there are higher frequencies, called harmonics, which have a similar effect; however, they're not nearly as bad, and can often be ignored.  It has been determined from experience that the very worst earthquakes tend to produce vibrations in the 2 to 4 Hz range, so the engineer designs a building so its natural resonant frequency falls outside this range.  So here's a tip: Find out what frequency the earthquake simulator produces.  Try to design your building so its resonate freq. is higher or lower than that.  You'll have to think a bit about this, and be ingenious!  The frequency can be calculated, but that involves solving some differential equations (I don't think you're ready for that, yet...)