Doesn’t weight times height lifted give you *work * (force x distance)?
[QUOTE=glee]
(snip)In fact, a concrete suspension bridge, the Tacoma Narrows Bridge, was destroyed by resonance vibrations set up by winds acting on the bridge. Today’s bridges are constructed to prevent or minimize this type of wind resonance effects.’
[QUOTE]
Sorry, this is an example of bad science propagated by lower level textbooks. It was wind, but NOT resonance. The actual mechanism of collapse of the Tacoma Narrows Bridge, (Galloping Gertie) was a good deal more complex. At the 42 mile per hour wind speed directly observed during the catastrophic failure of the bridge the frequency of the vibrations recorded were completely unsychronized with any natural resonance in the structure.
Here and here are a couple of links to more recent ideas about the bridge collapse.
Well, I tried this a bit myself, and it seems that by doing it rapidly, I’m more likely to accidentally use my wrist and arm muscles in the process.
Yes, but work is just another word for mechanically-transfered energy. You need energy to do work.