An ion's position vector is initially = (8.1 m)+ +-6.7 m )k, a 7 = (8.6 m )i + (7.3 m )3 + (1.1 m ). In In unit-vector notation, what is its average velocity during the 3.8 s? Number i i ))+ (1.1 + i .1 m ,and 3.8 s later it is k Units