Quote:
|
Originally Posted by Dr.Manjeet Singh
I think i understood some of what you are saying but i thought that that damping it is reduced if the tripod is heavy as the kit and if it has stable legs(the base of the legs is circler and heavy).Please tell me if i am wrong(i was a idiot in Physics.(p.s. oh as for tapping the lens i did -THE LENS FELL OF(AH).   Just joking-windyridge50 your explaination i did understand -and one of the best for slow learns like me but my question still remains-(above).Thanks and sorry for the bother. |
I think you have to think of mass, stiffness and damping as three independent variables. Obviously a heavy tripod is preferable, as for any given force input the resultant acceleration will be less, also a stiffer tripod is good for the same reason that for a fixed force input the displacement will be less. So I agree with you on this.
However once the tripod is in motion the vibration is controlled by damping. the normal way of expressing damping is by the use of a term called tan d (d is really delta but I can't get the symbol here) where tan d is the ratio of the imaginary to real component of the complex Young's modulus (E) where E*= E'+jE" and tan d=E"/E'. A structure with a tan d of 2 is called "dead beat" and for any given energy input will come to rest in less than one cycle of vibration, typical welded steel structures will have a tan d around 0.001.
Damping may be of the coulomb friction type (two bits of metal rubbing together, say in a bolted joint,) or may be tuned to a specific application by the use of a viscoelastic polymer treatment.
The general solution for any vibrating system, treated as a "lumped parameter" system is covered by a second order differential equation, but for higher frequencies, where "wave effects" can throw up a number of nasties in a "distributed system" a one-dimensional solution of the three dimensional wave equation provides a much more precise answer.
Hope this helps :-)