You can tell if vector is an unit because it has something to do with taking the magnitude of the vector.
also has a length 1. thus you should use pythagoras to check.
Hope this help
The 3rd one I think . I did something similar a while ago
F= a*m
F= 0.5 kg * 52m/s^2
F=26kgm/s^2 or 26N
The answer is B. Both NPN and PNP transistors consist of a base composed of an N-type material.