What is Bridge: Definition and 481 Discussions

A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving a particular purpose and applicable to different situations. Designs of bridges vary depending on factors such as: the function of the bridge, the nature of the terrain where the bridge is constructed and anchored, and the material used to make it and the funds available to build it.
The earliest bridges were likely made with fallen trees and stepping stones. The Neolithic people built boardwalk bridges across marshland. The Arkadiko Bridge (dating from the 13th century BC, in the Peloponnese) is one of the oldest arch bridges still in existence and use.

View More On Wikipedia.org
Recent contents Top users
  1. ernd59

    Power electronics : half bridge vs H bridge

    what is the the Difference between the a H bridge and half bridge power inverter? i mean both do the same job ? what are the pro and contra of using a half/H bridge ? and how would it effect the size of a transformer if I am using one thanks
  2. E

    Two balls thrown from bridge one upwards, other downwards?

    I would have thought the force of a persons arm being thrown downwards (with gravity) would essentially increase a balls initial downward acceleration immediately following the balls release. As compared to an upwards thrown balls initial acceleration; in which the persons upwards arm movement...
  3. CMATT

    What is the wave speed in the bridge?

    Homework Statement A certain pedestrian bridge in England resonates like a string fixed at both ends. If the bridge is 73.0 m long and its fundamental resonance is at 0.600 Hz, what is the wave speed in the bridge? Homework Equations Velocity = (frequency)(wavelength) The Attempt at a...
  4. M

    Length Contraction of Bridge rotated 30 degrees

    Homework Statement A Train is driving with a uniformed velocity. v=1/4 c. The train is driving under a bridge, which is rotated \theta=30 degree in relation to the railway. The bridges length is 20 m long in a reference frame of the bridge (stationary bridge). Calculate the length of the...
  5. Tabasko633

    Bridge from physics to biology

    Hey guys, so I am finishing my bachelor in physics and start to thing about my next steps. I am burning for very fundamental research topics but have a feeling that I lack the mathematical skill (or interest) to go deeper into theoretical physics. I started to read some literature on evolution...
  6. D

    How to calculate bridge deformation based on "design"?

    Homework Statement I'm not sure if this belongs here, sorry if it does not. I am trying to find the most amount of mass a bridge can hold before deforming/collapsing. I was trying to factor stress/ultimate tensile strength into it in a way. Is there a way I can calculate ultimate tensile...
  7. Ravyan Asro

    How does a Wheatstone Bridge work?

    I have never understood the concept of the Wheatstone Bridge and how it works. Even the following equations and numericals on this topic of platinum resistance thermometer confuses me a lot... I need help.
  8. B

    3 phase bridge uncontrolled rectifier, resultant waveform

    Hi all, Having difficulty understanding the above resultant wave form, been looking at power electronics (C.W.Lander) but don't quite get the addition of the wave forms (positive and negative cycles)can anyone point me to some reading of theory I am missing for this, thanks.
  9. T

    Calculating current in an unbalanced wheatstone bridge?

    I am having troubles understanding how to calculate the current at RSensor when RSensor is 110 Ohms. Any help would be appreciated.
  10. F

    Creating a Simultaneous Circuit: Exploring the Concept of Bridging Two Circuits

    Is it possible to have one part of the circuit running with electricity then manually add in a second part of the circuit to the first part and have both running simultaneously? Is there a name for such a circuit? The voltage and current of the first part of the circuit would change because of...
  11. andrewkirk

    What is the upper arch of the Sydney Harbour Bridge for?

    I was looking at the Sydney Harbour Bridge the other day, trying to work out how the weight of the roadway was transmitted to the ground. http://www.exploreaustralia.net.au/New-South-Wales/Sydney/The-Rocks/Dawes-Point/Sydney-Harbour-Bridge. You can see that there is an inner (lower) and outer...
  12. I

    Question on Statics -- San Francisco Bay Bridge Bolts

    Homework Statement http://cisephysics.homestead.com/files/NewSanFranciscoBridge.pdf My question is on this problem. For some reason, I have trouble seeing which direction the force is pushing when it comes to statics. In this case, why is the column pushing up? I thought it would be going down...
  13. H

    What Are the Tensions in Each Cable of a Suspension Bridge?

    Homework Statement [/B] A simple suspension bridge consists of a uniform plane horizontal rectangular roadway of mass M, freely supported by two sets of four equally spaced light vertical cables. Each set of four cables lies in the same vertical plane and is attached to one edge of the roadway...
  14. A

    The formulas for parallel and series connections

    Homework Statement Find the equivalent resistance between A and B. All resistances shown are in ohm. Homework Equations The formulas for parallel and series connections. The Attempt at a Solution I have attempted to redraw the circuit and my redrawn diagram looks like this. I don't think...
  15. J

    Automobile velocity on the bridge

    Homework Statement Automobile with m = 1000kg, traveling at v = 54km/h got to the bridge with curvature radius r = 50m. What is its velocity at the top of the bridge? Homework EquationsThe Attempt at a Solution If this solution is correct, could you please explain to me how can this...
  16. H

    Load moving horizontally across bridge, speed affect loading

    a load moves horizontally across a flat bridge, eg a train, does the time the load is on the bridge affect the vertical force on the bridge. put another way; can a bridge support a load greater than it's maximum load it can support for a stationary object if the load is only on the bridge for a...
  17. AnkurGarg

    Salt Bridge: Role in Half Cells Voltage

    In our textbook,it is written that-Salt bridge connects the solutions in 2 half cells and complete the circuit.If it is removed from a cell,then the voltage of the cell drops to zero. Doubt-What I think should come is-if salt bridge is removed,the positive ions accumulated in anodic half...
  18. R

    Bridge Beam Shapes: Why Are They Different?

    I pass a river with two bridges on it, right next to each other. One older, one newer. The newer one is all concrete construction & the shape of its spans makes intuitive sense to me i.e. minimum thickness at mid span. Like this sketch: The older one has sort of the opposite shape with max...
  19. G

    Advantages of a half bridge over a full bridge (wheatstone)

    Homework Statement Hi Guys, I know that, when measuring strain using gauges, using a full wheatstone bridge over a half bridge will give you double the sensitivity (Vout = NEGS/4, with N=2 for half and N=4 for full). But why would you use a hald bridge over a full one? What are the advantages...
  20. B3NR4Y

    Current in Wheatstone Bridge

    Homework Statement The ammeter in the Wheatstone bridge of measures zero current when the resistance Rvar of the variable resistor is set to 193Ω . What is the current IL through the left side of the bridge? Homework Equations V1 + V2 + V3 + V4 + ... + VN = E Rx = Rvar*R3/R1 The Attempt at a...
  21. G

    Backyard suspension bridge calculations

    Hi there, I'm planning to build a suspension bridge in my backyard and i'd like some help with sag and force calculations. The bridge will span 18m across a stream (anchor to anchor) in my backyard. I'll have 2 x strands of wire rope (1 at either side of the walkway) to span the gap. I've...
  22. A

    Wheatstone bridge -- Why set all 4 resistances equal?

    Can someone explain me,why Wheatstone bridge is most sensitive when all four resistances say A,B,C and D are equal?as far as i know condition for Wheatstone Bridge is A/B=C/D.
  23. S

    Wheatstone bridge, only one R value known

    Problem statement, work done, and equations: I cannot figure how to get the other resistor values, seems like too few knowns A Wheatstone Bridge is often used in sensor circuits and other measurement circuits. The basic circuit is drawn below: In the circuit, Rs is the sensor and might be a...
  24. A

    Engineering Help with Wheatstone Bridge Strain Gauge Circuit

    Homework Statement Given your average Wheatstone Bridge with R1 R2 and R3 unknown resistor values and R4=RG= strain gauge, how to solve for the resistor values given only input voltage and the value of the resistances between the resistors?[/B]Homework Equations Not Sure[/B]The Attempt at a...
  25. STEMucator

    Engineering Bridge Rectifier Circuit Operation and Output Waveform Explanation

    Homework Statement The output of the transformer is a sinusoidal AC signal with ##10.6V## RMS amplitude, and acts as an input to the bridge rectifier. Explain the operation of the following bridge rectifier circuit. Then sketch the output waveform ##V_L## assuming the ##0.7V## drop model for...
  26. J

    Why the voltage acrossWheatstone's bridge isn't always zero?

    Homework Statement Wheatstone bridge. Homework Equations i Why the voltage across whetstone's bridge isn't always zero ? according to ohm's law . It must be zero (V=I*R, R=0) =>V=0 across the bridge . The Attempt at a Solution I think I'm missing something . the following sentence isn't...
  27. C

    Engineering Circuit theory -- Conditions to balance a resistive bridge circuit

    1. Homework Statement Establish the condition required to make the current through Ze in Figure 1 zero (i.e. For the voltage Vx to equal Vy). Homework EquationsThe Attempt at a Solution I'm not sure if I'm on the right line here, hopefully someone can point me in the right direction if it's...
  28. Rampart

    Bridge rectifier with capacitor

    Homework Statement For the following bridge rectifier you are asked to find the dc output voltage for the following errors: a)the capacitor is an open circuit b)one of the diodes is open c)the electrolytic capacitor is connected with reverse polarity The Attempt at a Solution My attempt is...
  29. K

    How High Is the Bridge Based on Projectile Motion?

    Homework Statement A rock thrown horizontally from a bridge hits the water below 30 meters away in the horizontal direction. If the rock was in the air for 2 seconds, how tall is the bridge? Homework Equations d=.5gt2The Attempt at a Solution I think I am going about this the right way. Just...
  30. P

    Single Phase Full Wave Controlled Bridge Rectifier

    Homework Statement For a bridge rectifier (4 thyristor) feeding an RL load having infinite inductance (to assume constant current) and a 100 ohm resistance, calculate for firing angles of 90°, 120° & 150° the average DC voltage and current. The bridge supply is 200V RMS. Draw Waveforms of...
  31. AdityaDev

    Can Jugglers Cross a Bridge with 5 Balls and a Weight Limit of 50kg?

    I was thinking about a situation where you have an expert juggler who carries 5 balls. He wants to cross a bridge which can only handle a total weight of let's say 50kg. (These values are randomn). And let's say the juggler weighs 45kg. Each ball weighs 2 kg. Can he cross the bridge by juggling...
  32. P

    Single Phase Full wave controlled Bridge Rectifier RL Load RMS V & I

    Hi, For a single phase full wave fully controlled bridge rectifier carrying a RL load, how is the RMS voltage and current calculated? I have researched textbooks but can only seem to find RMS equations for Resistive loads and I am not sure whether the negative load voltage will affect the...
  33. T

    Does anyone know what a Dielectric loss angle bridge is?

    All I can find on google is about what the dielectric loss angle is. I imagine the bridge is something like a Whitstone bridge but for this... Thanks
  34. S

    Calculating Torque on a Drawbridge: A Challenging Project

    Suppose I have a four foot high rectangular slab that weighs 100 pounds, and is hinged at the bottom. The slab is essentially a draw bridge. It is anchored at the by two chains on either side. A winch can lower and raise it. Suppose the slab is at 45 degree angle. How much torque is there in the...
  35. E

    Is Haswell worth upgrading from Ivy Bridge?

    Is it worth the money upgrading from an Ivy Bridge to a Haswell or Haswell-E? Clock for clock, about how much faster is the new microarchitecture?
  36. I

    Analyzing RTD/Wheatstone Bridge Circuit: Varying R2 and R3 Values

    Homework Statement Currently writing a report about a Wheatstone Bridge circuit with RTD sensor. The sensor is to work between 0°C and 100°C and output 0 mV to 10 mV. Rx has a nominal resistance, Rn of 100 Ω, Vs=10 V and α=0.00385 °C-1. Therefore RT = 138.5 Ω Assuming RT is in the bottom...
  37. Laurine

    Solving the Severn Bridge Sag Span Mystery

    Hello everyone. I have to describe is the Severn Bridge, a suspension bridge spanning the River Severn and River Wye in England. I have found almost all the measurements, except for one: the sag span. I could only find the sag ratio (1/12) but I need to convert this ratio to meters. Can anyone...
  38. gracy

    Salt Bridge: Maintaining Charge Flow in External Circuits

    Without the salt bridge then there is no flow of charge and there are no electrons flowing in the external circuit.?HOW?i know function of salt bridge is only to maintain neutrality i.e if salt bridge is not there there will be accumulation of positive charge in one half cell and negative charge...
  39. H

    Designing a Spaghetti Bridge to Support 2kg of Sand: Tips and Restrictions

    Hey y'all, I am in the 11th grade and have been assigned a spaghetti bridge project. Our teacher taught us nothing about bridges or structures, but only the basic forces. We were instructed to research designs of bridges online but every website or forum that I have found has had a different...
  40. J

    Understanding Bridge Sensitivity and Checking Vout Expression for Accuracy

    Can anyone tell me if my Vout expression for this bridge is correct or can correct me if there is anything wrong. Vout = 10{(Rt/100+Rt)-1/2}
  41. P

    Wheatstone bridge problem unable to understand

    Homework Statement The bridge circuit below is used to monitor temperature using a thermometer. The thermometer RT has resistance of 100 Ω at 0°C and a linear coefficient with temperature of 0.005 Ω/°C. What is the sensitivity of the bridge (ΔVOUT/ΔT) around 100 °C for ΔT = 1°C? How does it...
  42. C

    Some books to bridge the gap before GR

    Hi all, I am extremely interested in GR, but somehow feel that the books I read are not really enough. Frankly, I find many question on this site and elsewhere completely bewildering, which makes me think that I don't have a solid foundation, especially in classical mechanics and various...
  43. M

    Is there any simulation software for Balsa Bridge ?

    Is there any simulation software for Balsa Bridge ?
  44. Chacabucogod

    Troubleshooting H Bridge Inverter Boost Issues

    I'm building a boost inverter, and when I connect two trasnsistors, an npn and a pnp, to the output resistance, and connect these two transistors to voltage it works. Now, when I connect the other two transistors and connect them to ground the boost stops working. Would anybody know what's going on?
  45. P

    Thevenin's equivalent of wheatstone bridge

    Hi guys, I tried to calculate the Vos and Isc and both of them are zero..so the Thevenin's resistance is 0/0=undefined. How do I calculate the resistance when Vos/Isc fails,such like the wheatstone bridge?
  46. Dethrone

    MHB Bridge Question - Stress / Strain

    I have gathered all the information: Span: $1991$ m Breaking Stress: $1770$ MPa Load: $370$ KN/m Drape: $201.2$ m So far, I've found the allowable stress by dividing the breaking stress by the safety factor, which is $787$MPa. Then, I calculated the total load of the bridge, by multiplying the...
  47. E

    Engineering A Kirchoff's Law problem with a bridge circuit

    Homework Statement I want to use Kirchoff's current law to analyze the pictured curcuit and find the current drawn fro the voltage source between the positive terminal and node 1. [PLAIN]http://s42.photobucket.com/user/Jemspak/media/circuitdiagram.jpg.html" (i can't figure out how to...
  48. I

    Bridge rectifier output voltage

    Hi, I'm trying to figure out why the output voltage waveform of this circuit would not include a DC offset of E. My understanding is that D1 becomes forward biased when Vs > E, and so that is when it should conduct. Every waveform drawing I've seen, on the other hand, begins conduction at 0...
  49. J

    Wheatstone Bridge Experiment.

    Hello Forum, I did an experiment on a Wheatstone bridge. We are to calculate the theoretical resistance of a given set of wires, then by using a value closest to the theoretical we are to set the resistance on a decade box. After the resistances are set we try to find the point on the bridge...
  50. Hardik Batra

    Meter Bridge Experiment: Limitations for Measuring Small Resistance

    why the meter bridge experiment not useful for the measurement of small resistance?
Back
Top