In mechanics, a force is that which causes a change in velocity or, if you prefer, that which causes an acceleration. When more than one force acts on an object it is the net force that is important. Since force is a vector quantity, use geometry instead of arithmetic when combining forces.
Quick Answer. A crawling sensation felt on the skin may be caused by a condition called morgellons, according to WebMD. Common symptoms of morgellons include feeling like bugs are crawling on the skin, burning, itching and stinging sensations. In some cases skin sores may appear as well.
MAIN MORGELLONS SKIN SYMPTOMS: In regard to the symptoms, in the initial stage one may experience increased crawling sensation, mostly around the scalp, nose and mouth. This is individual and is caused from colored hyphae/filaments/fibers (black specks) that are growing out of skin pores. In the second stage is noticed, a biting and stinging sensation which is later followed by an itching.