<u>We are given:</u>
The tuning fork vibrates at 15660 oscillations per minute
<u>Period of one back-and forth movement:</u>
the given data can be rewritten as:
1 minute / 15660 oscillations
60 seconds / 15660 oscillations <em>(1 minute = 60 seconds)</em>
<em>dividing the values</em>
0.0038 seconds / Oscillation
Therefore, one back and forth vibration takes 0.0038 seconds