Set the rotation rate of the motor as near to 1000 rpm's as possible.  The LabQuest Mini interface must be used for this demo if you wish to continually monitor the rpm and rps.  Use the LoggerPro program "Tachometer" to monitor this (Note: The "Tachometer" program is set so that it counts each break of the photogate by the spokes of the pulley wheel and then divides by 6 which gives the true rpm's of the motor).  Set the flash rate of the strobe light to the same rpm setting of your motor.  When both are running the pulley of the motor should appear to stand still.  By increasing the strobe rate to several Hertz above the rpm rate of the motor, the pulley will appear to slowly turn in the clockwise direction.  When you decrease the strobe rate to several Hertz below the rpm rate of the motor, the pulley will appear to slowly turn in the counter clockwise direction.

NOTE: The LabPro interface can be used for this demo but will only allow you to monitor the rpm's of the wheel but will only give good data when the strobe light is off.  When the strobe light is on, it spuriously triggers the photogate.  So, set the motor speed first, then do the demo.