Answer:
(a) 
Average velocity = < 0, 316000, 146000> m/s
(b) < 0, 2.844, 1.314 > m 
Explanation:
r1 = < 0.02, 0.04, - 0.06 > m
r2 = < 0.02, 1.62, - 0.79 > m
time, t = 5 micro second = 5 x 10^-6 s 
(a) Average velocity is defined as the ratio of total displacement to the total time taken. 
Displacement = r = r2 - r1 
r = < 0.02 - 0.02, 1.62 - 0.04, - 0.79 + 0.06 > m 
r = < 0, 1.58, - 0.73 > m 
So. Average velocity =  
Average velocity = 
Average velocity = < 0, 316000, 146000> m/s
(b) 
Distance = velocity x time 
Here time, t = 9 micro second 
d =  < 0, 316000, 146000>  x 9 x 10^-6 m 
d = < 0, 2.844, 1.314 > m