Frequency to employ in movement study using a ticket timer

Abstract

In  practice  of  movement  in  physics  laboratories  commonly  use  ticket  timers  and  the laboratory guides indicate that a frequency of 60 Hertz is used. Which is corresponding to the frequency of the domestic electrical system; the use of a frequency of 60Hz gives incorrect results  in  such  practices.  This  article  is  intended  to  show  that  the  frequency  to  be  used  in these  practices  of  movement  should  be  120  Hertz.  To  demonstrate  this  we  proceed  to  use the ticometer in a practice of freefall, to find that the use of this frequency gives reasonable results  for  the  value  of  the  gravitational  acceleration  of  the  earth  near  the  earth’s surface. Using the frequency of 120 Hertz is based on the fact that the coil magnetizes the ticometer both  the  positive  phase  and  the  negative  phase  of  the  current  of  the  electrical  system  and in each magnetization phase of the coil the firing pin is attracted to hit the tape and mark a point which explains why it has two points in a cycle.