question_answer

Two clocks are being tested against a standard clock located in a national laboratory. At 12:00:00 noon by the standard clock, the readings of the two clocks are: Day Clock 1 Clock 2 Monday \[\text{12}:00:0\text{5}\] \[\text{1}0:\text{15}:0\text{6}\] Tuesday \[\text{12}:0\text{1}:\text{15}\] \[\text{1}0:\text{14}:\text{59}\] Wednesday \[\text{11}:\text{59}:0\text{8}\] \[\text{1}0:\text{15}:\text{18}\] Thursday \[\text{12}:0\text{1}:\text{5}0\] \[\text{1}0:\text{15}:0\text{7}\] Friday \[\text{11}:\text{59}:\text{15}\] \[\text{1}0:\text{14}:\text{53}\] Saturday \[\text{12}:0\text{1}:\text{3}0\] \[\text{1}0:\text{15}:\text{24}\] Sunday \[\text{12}:0\text{1}:\text{19}\] \[\text{1}0:\text{15}:\text{11}\] If you are doing an experiment that requires precision time interval measurements, which of the two clocks will you prefer?

Answer:

                The range of variation over the seven days of observations is 162 s for clock 1, and 31s for clock 2. The average reading of clock 1 is much closer to the standard time than the average reading of clock 2. The important point is that a clock's zero error is not as significant for precision work as its variation, because a 'zero-error' can always be easily corrected. Hence clock 2 is to be preferred to clock 1.