  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.
If a cough is caused by allergies or asthma, it will usually go away when the other symptoms of the illness subside. Ad. Bronchitis is another illness which may sometimes cause a dry hacking cough.A person with bronchitis may have a dry cough as one of the first symptoms of being ill. dry hacking cough could also be caused by the common cold and other viral infections. The cold virus can enter the body through the nose and travel to the throat. The cough is one of the body's reactions to the virus â an attempt to expel the virus and prevent infection.