science project. Needs to be verry stable. Not an actuall bridge. A model.
121543
use trusses. basically triangles. if u wanna do it easily, use 45 degree angles. to make it more stable use 30 and 60 degree angles. so basically make each side first and then to connect between them, i have no clue but dont do it straight across. u have to connect the top of the left to the bottom of the right. o rsomethin
589839
Hope this helps you out , you might want to download a program called webferrett it will find just about anything \n\nwww.redstoneprojects.com/trebuchetstore/build_a_catapult.html
332490
I just helped my daughter with her science project. We made an electromagnet. Very easy to build and you can get buzzers, lights, and battery holders a your nearest hobby Lobby. you can also get toggle switches at the local hardware store. Mount it all on a nice piece of wood and your in business. by the way, my daughter took home first place!
175302
Try the ASCE research library it has some good articles on civil engineering.\nYou will have many options to choose for example you can choose bridges
72268
the needed papers/license to build something like that.\n\nThe construction should be checked also before building (strong enough etc)
492930
Ok. this is simple. u need to know about buyoancy, like how air is lighter than water. all you really got do is put some small weights (ex. paper clips, rocks, etc) in the bottle. have it so that it will just barely float. then cut a hole to the side and insert the end of a tube in it. make sure it is water tight. then place it in a tub. it shold float, when you suck on the end of the tube, it should take some of the air out making it less buoyant, and therefore it will sink. there are also many other ways to do this that will make it function more like a real submarine like putting the bottle with weights inside and somehow add pressure to the the outside of the tube to compact the air inside the bottle, causing it to sink. good luck on your project
504677
How big should this be?\n\nWell, you want to make it slightly arched with a flat road.\nAll triangles for the joints.\n\n.______\n/&#92;/&#92;/&#92;/&#92;/&#92;/&#92;/&#92;
568148
what about building a;\n\nGyroscope, digital compass, a wireless motion sensor, temperature sensor, force sensor, speed sensor, preasure gauge, etc\n..... for physics i'd try build some kind of sensor just so that you can measure various variables
189078
I'd say the triangle; that is why most bridges are built with a "Triangle Truss." It makes the bridge more stable.
2621
here's a site with pics that might give you some ideas:\n\n\nhttp://www.physics.usyd.edu.au/competition/comp1998/comp98.html
625972
This problem is already solved. You know about those guys doing "base jumping"?\n\nTo really answer your question I would suggest a reinforced sphere with a chair in the center contained in an inner reinforcement cage which is attached to the surface of the sphere with springs (in all directions). You have to be very well strapped in the chair (maybe like in a high end  rollercoaster).\nI'll make some calculations but I think the diameter of the sphere should be kinda big (to have a longer stoping distance) in order to avoid high G values
344064
the smaller one would be stronger, as it would not suffer as much tensile stress (or strain) per volume area..... all materials have a certain amount of pressure and stress they can withstand before buckling or deforming in someway, and is known as 'youngs modulus' (this is a ratio between the stress and strain limits of a material). the forces on a bridge that enginneers worry about are more often that caused by the bridges own structure than of vehicles and other things across it, such as the weight of the steel and concreate been pulled down between two supporting pillars by gravity, or the weight carried on suspension cables.\n\nso even if the scale was increased 5 times, the limits of the material (steel for example) would not increase, the thicker the steel supports, the more spread the pressure (force over area) is, tru..., however, this is not sufficient enough to support the new weight load; for example... imagine a cylindrical steel support.... even if the scale increased 5 times, the forces would exceed the limits, the structure would be 5 times greater... but unless the limits of the material became 5 times greater... it would not hold....\n....... i think.\n\nhope that helps!\n\nthat psychics explanation!!!
611564
what's the boundary conditions?\nself weight problem? \nthen, what's the material of the beam?\n\npls be clear :)
424669
I will try. \nNot because it is difficult to understand but difficult to describe. Let us take a three member truss.\n\nA truss must be in equilibrium otherwise it will fall into its three component pieces. Lets assume it is for a roof\n\nFrom its apex to the two walls its load will come from the tiles, and for these the angles and weights are calculated to establish what portion of it goes to which joint.\nThe two portions at the top are examined together to make sure their loads will be stable against each other.\nThe portions at the bottom are being supported by two walls but they have two components each. One wants to rest on the wall while the other is trying to move away from the wall.\nTo keep this from happening we have to introduce our third truss member and make sure it can take the tension required of it.\nNow we know all the points we can show the summation of all the loads and ascertain if they are in compression or tension.\nWhen we have selected or designed each of our truss members we can fix them to keep the whole assembly stable.\nNow the truss it in equilibrium.\nTry it with large match sticks and think of what you are reading.\nIt might help.
319182
Not a site, but I suggest you invest in something called Mathcad.\nTeach, please note, it is a site not a sight! Unless you were 'looking' for the answer... sorry!
469263
Don't you just need to balance forces in orthogonal directions and then use these components to get the forces along the cable?\n\nSince the sign is stationary, vector sum of forces must be zero.  Sketch a free body diagram and label known forces.
440553
Yeah...good luck with that.  By the way, do you want to buy a bridge?