virtually and practically are synonyms - meaning all but, nearly. Practically usually refers to practical purposes, however its meaning has been extended to mean 'nearly, all but'.
This paper has virtually no mistakes. (practically - sounds wrong here).
The car was practically undrivable. (virtually - sounds less right to me).
actually means:
1 really. Example: She actually saw the accident
2. in fact Example: Actually, I'm doing something else this evening.
Physically means:
In a physical manner; according to the laws of nature or physics; by physical force; not morally.
Example: He physically grabbed the thief and threw him out of the house.