Indeed in an inertial frame the fictitious force vanishes (from the analysis) as a force, but it also magically reappears as mass times acceleration, simply going from the left hand side to the right hand side of F=ma while changing sign, so the equations remain the same mathematically.
For example if one analyses the motion of a satellite on a circular orbit in its rotating frame, the satellite is at rest i.e. the sum of the inwards gravitational force Fg and of the fictitious outwards centrifugal force mv^2/r is zero: F = m*a Fg - m*v^2/r = 0 If one now analyses the satellite's motion in the (assumed inertial) frame of the Earth, the centri_fugal_ force -mv^2/r moves to the right while changing sign to become m times the centri_petal_ acceleration +v^2/r : F = m*a Fg = m*v^2/r Same equation mathematically, so both approaches yield the same result for orbital speed as a function of radius as would be expected. Michel ----- Original Message ----- From: "Stephen A. Lawrence" <[EMAIL PROTECTED]> To: <vortex-l@eskimo.com> Sent: Wednesday, February 28, 2007 10:30 PM Subject: Re: [Vo]: Re: lifter in a accelerating frame ... > A "fictitious" (or "inertial") force is one which appears in an > accelerated reference frame, and can be made to vanish (from the > analysis) by performing the analysis in an inertial frame.
