In the demonstration, 360∘ of rotation (one full rotation) represents a sidereal day. you can actually measure the length of the sidereal day by measuring the time from when crosses your meridian on one day (or night) until it crosses the meridian on the next day (or night). mastering astronomy

Leading guitar string producer wound up inc. has enjoyed a competitive advantage based on its proprietary coating that gives its strings a clearer sound and longer lifespan than uncoated strings. one of wound up's competitors, however, has recently developed a similar coating using less expensive ingredients, which allows it to charge a lower price than wound up for similar-quality strings. wound up's competitive advantage is in danger due to a. a lack of perceived value b. a lack of organization c. direct imitation and substitution d. resource immobility