Bridges. Why they don't fall down. 

Corrected Title: "Bridges. Why they don't immediately fall down." They all do eventually, and many are in the US.

for your gearbox, i have an idea, use a heavy flywheel, and a clutch (maybe rip one from like a lawnmower, they have on/of switch clutches which is good for this situation) and build up speed with the fly wheel, and then enable the clutch, getting a huge burst of speed and weight for good torque, and who knows, it could explode, it could work

I love how your actually doing a deal with them. Lots of people say it’s free and then scam

I hate watching Micro Center adds, it makes me jealous. I wanna store like microcenter in my country

What is your favorite game ?

Poly Bridge says hi!

You should get poly bridge!

Poly bridge 1 or 2?

@@jackmaldonado1186 Both?

oh hello i watch you!

Thanks!

If the arch is under the bridge, then it loads the equivalent of cables in compression, and cables would be insufficient. You'd need a truss to put the arch under the bridge. The idea is, that tension is the cheapest internal load to support, because tension only requires that your member withstands normal stress that is very close to uniformly distributed in the cross section. Compression also only stresses the members in normal stress, but an entirely new failure mode happens for compression, called buckling. Both of these loads are a lot cheaper to support than bending loads, which systematically put a non-uniform stress distribution in the cross section, which is why most bridges aren't simple platforms, except for small footbridges. Therefore, we want as many members as possible to be in tension. And where compression is needed for the construction of trusses, we try to make the shortest members be the members in compression, to minimize the material needed to resist buckling.

If the arch is under the bridge, then it loads the members that would take the place of cables in compression, and cables would be insufficient. You'd need a truss to put the arch under the bridge, and have some rigidity to the members to resist buckling. The idea is, that tension is the cheapest internal load to support, because tension only requires that your member withstands normal stress that is very close to uniformly distributed in the cross section. Compression also only stresses the members in normal stress, but an entirely new failure mode happens for compression, called buckling. Both of these loads are a lot cheaper to support than bending loads, which systematically put a non-uniform stress distribution in the cross section, which is why most bridges aren't simple platforms, except for small footbridges. Therefore, we want as many members as possible to be in tension. And where compression is needed for the construction of trusses, we try to make the shortest members be the members in compression, to minimize the material needed to resist buckling.

F=kx

arc transforms bending to compression

ie vertical to horizontal

a man has fallen into a river in lego city