The term business cycle refers to economy-wide fluctuations in production, trade, and general economic activity. Identify features of the economic business cycle. Business cycles are identified as having four distinct phases: expansion, peak, contraction, and trough. An expansion is characterized by increasing employment, economic growth, and upward pressure on prices.
The speed of light in a given material is related to a quantity called the index of refraction, n, which is defined as the ratio of the speed of light in vacuum to the speed of light in the medium: index of refraction: n = c / v.When light travels from one medium to another, the speed changes, as does the wavelength.efraction. When we talk about the speed of light, we're usually talking about the speed of light in a vacuum, which is 3.00 x 10 8 m/s. When light travels through something else, such as glass, diamond, or plastic, it travels at a different speed.
Let's add a few words to them to clarify.  Nothing can travel faster than the speed of light in a vacuum.  . Light in a vacuum always travels at the same speed.  Those additional three words in a vacuum are very important. A vacuum is a region with no matter in it. So a vacuum would not contain any dust particles (unlike a vacuum cleaner, which is generally full of dust particles). Light traveling through anything other than a perfect vacuum will scatter off off whatever particles exist, as illustrated below. In vacuum the speed of light is c = 2.99792458 x 108 m/s.