  A scalar has only magnitude. A vector has magnitude and direction.   Acceleration is a vector because it has magnitude and direction. That's why an o â¦ bject can be said to be accelerating if it has a circular rotation and a constant speed; even though it's speed isn't changing, it's direction constantly is. vector has magnitude and direction.   Acceleration is a vector because it has magnitude and direction. That's why an o â¦ bject can be said to be accelerating if it has a circular rotation and a constant speed; even though it's speed isn't changing, it's direction constantly is.
Chronic dry coughs are usually caused by irritation from cigarette smoke, environmental irritants, allergies, postnasal drip, or asthma. Several chronic lung diseases also cause a dry, hacking cough. Some people cough out of habit for no clear reason. Gastric reflux may also cause a chronic dry cough. Usually you will also have other symptoms, such as heartburn, burning in the throat, or increased saliva.
A cough may be described as being dry, wet, productive (meaning you cough up mucus and/or sputum), or non-productive. Even the way a cough sounds can give us a pretty good clue as to what is going on. A dry cough may be caused by an allergy, cold, flu, or the beginning of bronchitis. A wet, productive cough could be the result of pneumonia, bronchitis, or the flu. A wet, nonproductive cough may also suggest a cold, flu, or bronchitis. A painful cough is frequently seen with pneumonia or bronchitis.