It's the same dilemma that you get into when you start trying to explain the
"Holes" theory of electrons in current flow!!! :)
Joe
> Bill Babcock wrote:
>
> You've just set science back at least four hundred years. "Seek the piston"?
>Is phlogiston involved here somewhere?
>
> -----Original Message-----
> From: Joe Curry [mailto:spitlist@gte.net]
> Sent: Wednesday, June 20, 2001 2:47 PM
> To: Mark J. Bradakis
> Cc: fot@autox.team.net
> Subject: Re: GT-6/Spitfire brakes
>
> Once again,
>
> In a stationary system, with a constant source of pressure, this is the case.
>
> But the system does not have a constant pressure and the slave cylinder
>moves, so it is not a stationary system.
>
> The fluid will travel along the path of least resistance and seek the piston
>when pressure is applied. Pressure on the input end (master cylinder)
>
> shows up on the other end as movement of the slave cylinder system. The
>amount of energy put into the system is going to be equal to the energy
> that
>
> is gotten out of the system (see the law of conservation of matter and
>energy). If the slave cylinder is smaller than the master cylinder, it
> stands
>
> to reason that that amount of energy will be concentrated on a smaller area
>and therefore will be expressed by a smaller piston as a greater force
>
> applied to the brakes or clutch.
>
> Now, that makes sense to me (May not be correct, but it certainly makes
>sense)!!! :)
>
> Joe (C)
>
> "Mark J. Bradakis" wrote:
> >
> > If you take the same setup and apply the 10 psi to a 0.5 square inch
> > piston you are now getting 10 lbs per 1/2 square inch which is 20 psi and
> > you get 20 lbs. of force out of the system.
> >
> > No, you don't. This is nonsense. If you have a pressure of 10 psi (that's
> > pounds per square inch), you have a pressure of 10 pounds per square inch,
> > over every single bit of area in the entire system. The insides of the
>brake
> > or clutch line, the bore of the fittings, against the base of the bleed
>screw,
> > *any* area inside the system will have that same force.
> >
> > If that pressure is applied to 1 square inch, you get 10 pounds of force.
> > If that pressure is applied to 2 square inches, you get 20 pounds of force.
> > If that pressure is applied to 1/2 square inch, you get 5 pounds of force.
> >
> > The force in pounds is the product of the area times the pressure, simple,
> > basic high school math. Write out the equation, and see how the units
>cancel:
> >
> > pounds pounds inch * inch
> > Force ------- = Pressure ----------- x Area ------------
> > 1 inch * inch 1
> >
> > This is classic Newtonian physics. The work that goes in is the same as
> > the work that comes out. That is, negating the effects of mechanical
>friction
> > and things like the force used to distort the clevis, the pins, etc. on
>every
> > pedal application. Here I use work in the classic physics definition, a
>force
> > applied over a distance.
> >
> > People are confusing volume, pressure, area and distance in the situation.
> > They are all related by basic mathematical equations.
> >
> > mjb.
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