  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 dry cough is known as ânonproductiveâ; whatâs called a wet cough is âproductiveâ (i.e. mucous-producing). The most common causes of a dry cough are asthma, allergies and acid refluxâin which other symptoms may or may not be present. Asthma Asthma, a condition in which the bronchial tubes become inflamed, usually causes wheezing, tightness in the chest and shortness of breath.