The phase velocity of a wave tells us how fast any given phase of the wave is moving e.g. the crest. If we examine some fixed position, then we can count how frequently a full wavelength passes this position as the wave moves with time. This leads us directly to $v = Î»f$.
Beverly Hills, Michigan, in Oakland county, is 3 miles N of Southfield, Michigan and 16 miles NW of Detroit, Michigan. The people of the town are in the Detroit metropolitan area.
Farmington Hills is a community in southeastern Michigan. It is the largest city in Oakland County in the U.S. state of Michigan. Its population was 79,740 at the 2010 census. It is a northwestern suburb that lies on the border of Metropolitan Detroit and is also 33 miles (53 km) northeast of downtown Ann Arbor.