Answer the following questions about the physical quantity acceleration.
a. (i) Define acceleration and state its SI unit.
b. (ii) Explain why acceleration is regarded as a vector quantity and not a scalar.
c. (iii) A sprinter runs southward, increasing his speed from 2m/s to 8m/s in 3s. State whether his acceleration is positive or negative with respect to the chosen southward direction and give a reason for your answer.