The time is recorded from three different clocks as indicated below. The "true" time is exactly 8:30 A. M.

Which of the three clocks is the most precise?

Which clock is the most accurate?

Which clock (s) show a systematic error?

Measurement Clock A Clock B Clock C

1 8:25.20 AM 8:29 AM 8:36 AM

2 8:25.00 AM 8:31 AM 8:36 AM

3 8:25.10 AM 8:30 AM 8:36 AM

Precision is the stability of the results of each clock so Clock C is the most precise.

Accuracy is the closeness to the actual value so Clock B is the most accurate.

There is a systematic error if the accuracy cannot be fixed but the precision can be increased by increasing the number of times the measurement is taken so Clock C has a systematic error.