What is the definition of a second? a. The time it takes a Cs-133 atom to comple
ID: 1657232 • Letter: W
Question
What is the definition of a second? a. The time it takes a Cs-133 atom to complete a certain number of vibrations. b. Exactly 1/86,400 of a day. c. The time it takes light to travel 3 m in a vacuum. d. One tick of the second hand of a watch.What is the definition of a second? a. The time it takes a Cs-133 atom to complete a certain number of vibrations. b. Exactly 1/86,400 of a day. c. The time it takes light to travel 3 m in a vacuum. d. One tick of the second hand of a watch.
What is the definition of a second? a. The time it takes a Cs-133 atom to complete a certain number of vibrations. b. Exactly 1/86,400 of a day. c. The time it takes light to travel 3 m in a vacuum. d. One tick of the second hand of a watch.
Explanation / Answer
second is defined as
the fraction of 1/ 86400 of the mean solar day
so correct answer is ................................ b