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.
Fungal rashes are skin infections caused by two specific types of fungi: tinea and candida. Tinea infections, also known as ringworm, are oval or ring-shaped lesions with normal-looking skin in the middle and an itchy, scaly, and slightly raised edge around it. The rash can be found on the scalp, face, body, or nails.