Which of the following would serve as the best time standard? ...

[craiczarry]

Which of the following would serve as the best time standard?
  1.the rotation of Earth upon its axis
  2.the vibration of a CS-133 atom
  3.a grandfather clock
  4.the buzzing of a mosquito

Question 2

Which of the following wavelengths is common to a 10 cm tube open at both ends and a 15 cm tube open at one end and closed at the other?
  1.60 cm
  2.30 cm
  3.20 cm
  4.15 cm
  5.5 cm
  6.Two of the above
  7.Three of the above
  8.None of the above

[tmlewis4706]

Answer to Question 1

2

Answer to Question 2

3

[craiczarry]

Thanks for the timely response, appreciate it

[epscape]

Excellent