A student runs toward the closed end of a hall while holding a vibrating tuning fork. The tuning fork is vibrating at 512Hz. The sound is reflected from the end of the hall back to the running student where 8.0 beats per second can be heard. Determind the speed of the student. i used the equation f' = f [(v +/- vo)/(v +/- vs)] 8 = 512 [(343 +/- 0)/(343 +/- vs)] and tried solving for vs to get the speed of the student, however the answer i got differed from what the teacher gave us, which was 2.6 m/s. I got 21609. Am i using the right equation?