Can anger be acceptable? When doing physical work, there are times that anger helps to overcome physical obstacles, as a way to arouse energy where force is required, but for the purpose of doing good (thru service, altruism), not harm. But anger is a form of aversion, a defilement, unhwholesome root. 

Did the Buddha say any words on whether the use of anger, or force, is ever acceptable?
There is no place for anger in Buddhism for any reason.
Right effort is what is required.