  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.
Many times when there is a change in weather, especially if it is onset of dry weather, then it leads to dryness in the upper portion of the throat. Sometimes, that also causes cough. Asthma: Asthma is another common cause of coughing. In such a case, inflammation of the pharynx or larynx causes cough and eventually, start a headache.