SI: second and hertz Mystery Cache

The International System of Units (SI), commonly known as the metric system, is the international standard for measurement. The SI plays an essential role in international commerce and is commonly used in scientific and technological research and development. This cache is part of the SI geoart that allows you to learn about the SI units. Visit the introduction cache to learn more about this geoart.

Time: second (s)

The second is the SI base unit of time. 1 second is defined to be exactly “the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom” (at a temperature of 0 K).

Multiples of seconds are usually counted in hours and minutes. While these are not SI units, they have a long history of consistent use and have been accepted for use with SI.

Fractions of a second are counted in:

• milliseconds (ms): 1/1000 of a second.
• microseconds (μs): 1/1000000 of a second.
• nanoseconds (ns): 1/1000000000 of a second.

milli-, micro-, and nano- are three examples of SI prefixes that precedes a basic unit of measure to indicate a fraction of the unit.

Frequency: hertz (Hz)

The hertz is the SI derived unit of frequency. It is defined as one cycle per second.

Hertz is commonly used to describe musical tones. For example, A4 concert pitch on a piano has a frequency of 440.000 Hz.

Hertz is also used to describe sine waves, especially those in radio related applications. Multiples of a hertz are counted in:

• kilohertz (KHz): 10³ Hz
• megahertz (MHz): 10⁶ Hz
• gigahertz (GHz): 10⁹ Hz

kilo-, mega-, and giga- are also SI prefixes that precedes a basic unit of measure to indicate a multiple of the unit.

This Geocache

At middle C frequency, how many cycles of vibration occur in 1716190 microseconds? Round this to an integer to get ABC.

What’s the nominal frequency of mains electricity near GCHJCN? Subtract 22 to get DEF.

Final coordinates: N 39° 07.ABC W 077° 09.DEF

You can validate your puzzle solution with certitude.

Cache container is a baby-nano with tiny log sheet. A pair of tweezers is mandatory for log retrieval. To conserve space, please omit the date and write the first two letters of your username only.

Some hides are located along a road without sidewalk. For your safety, please walk on the grass out of the car lanes, and avoid going at night without wearing a safety vest.

Lists of Caches in SI geoart

0. introduction
1. second and hertz
2. metre
3. kilogram
4. m/s and km/h
5. mole
6. radian and steradian
7. m/s² and newton
8. m² and pascal
9. joule and watt
10. ampere and coulomb
11. volt and farad
12. ohm
13. kelvin
14. candela, lumen, and lux
15. bushel
16. foreword & afterword
17. prize distribution