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.
(4.6 billion years ago). When Earth formed 4.6 billion years ago from a hot mix of gases and solids, it had almost no atmosphere. The surface was molten. As Earth cooled, an atmosphere formed mainly from gases spewed from volcanoes. It included hydrogen sulfide, methane, and ten to 200 times as much carbon dioxide as todayâs atmosphere. After about half a billion years, Earthâs surface cooled and solidified enough for water to collect on it.