# The Period of a Recording Timer

Topics: Stroboscope, Ticker tape, Power Pages: 2 (261 words) Published: November 10, 2012
The Period of a Recording Timer

Problem

What are the period and frequency of a recording timer?

Materials

recording timer
power supply
approximately 2 m of ticker tape
carbon paper disk
stopwatch

Procedure

1. Connect the timer to the power supply.
2. Set up the carbon paper (carbon side down) and ticker tape. 3. Start the timer.
4. One person starts timing when another person starts pulling the ticker tape. 5. Stop timing when the ticker tape leaves the timer.

Observations

Number of dots: 128 dots
Time (in seconds): 1.69 seconds

Calculations

T= sdotsf=dotss

=1.69s128 dots =128 dots1.69s

= 0.013s/dot = 75.7dots/s

Discussion Questions

1.

Range: 0.011s/dot to 0.015 s/dot
Range: 0.011s/dot to 0.015 s/dot
2. T=0.013s/dot
0.013s/dot x 18% = 0.00234s/dot
0.013s/dot + 0.00234s/dot = 0.015s/dot
0.013s/dot – 0.00234s/dot = 0.011s/dot

3.f=75.7dots/s
Range: 62.1 dots/s to 89.3 dots/s
Range: 62.1 dots/s to 89.3 dots/s
75.7dots/s x 18% = 13.626 dots/s
75.7dots/s + 13.626 dots/s = 89.3 dots/s
75.7dots/s – 13.626 dots/s = 62.1 dots/s

4. Yes, because the period/frequency is constantly changing and the period/frequency calculated is only the average.

5. About 76 dots represent 1 s.

Conclusion

The period of the timer is 0.013s/dot, and the frequency is 75.7 dots/s.