So the frequency is f =10 cycles / 120 s = 0.0833 cycles/s. Answer: D. Frequency refers to the number of occurrences of a periodic event per time and is measured in cycles/second. In this case, there are 10 cycles per 2 minutes (also known as 10 cycles per 120 seconds).
From the scientific viewpoint, the Earth would have had to form about 4.54 billion years since the earliest material in the solar system is dated back to about this time period.
The Earth formed approximately 4.5 billion years ago, along with the other seven planets in the solar system. As the Earth cooled, a primitive atmosphere was created by the out-gassing of early volcanoes. The early atmosphere contained no oxygen and would have been toxic to human beings, as well as most other life on Earth today.