  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.
Asthma - Asthma may be a cause of a steady cough. It is often accompanied by wheezing and chest tightness, but in some people, a cough is the only symptom. Acid reflux - Gastroesophageal reflux disease (GERD) can result in constant coughing due to the back up of acid from the stomach. A very common cause of coughing, GERD often causes episodes of coughing at night after lying down and often results in hoarseness the following morning.