  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.
Post-nasal drip causes draining down the back of the throat and can cause a productive cough. A cold or asthma can provide someone with a less wet cough called a nonproductive cough, which is a dry cough that can sometimes cause the throat to become sore.ost-nasal drip can happen for many different reasons. Some of the most common causes are as follows: 1  Illness-colds and flus usually produce the most mucus. 2  Allergies. 3  Sinus Infection. 4  Dry air (heat from a furnace in the winter). 5  Foods (ones that make the nose run or that tend to build mucus like dairy products).