Answer the questions given below with reference to the terms "scalar quantity" and "vector quantity".
a. (i) Define a scalar quantity and a vector quantity.
b. (ii) State any two examples each of scalars and vectors that are commonly used in mechanics.
c. (iii) Is distance a scalar or a vector quantity? Give one reason for your answer.
d. (iv) Is displacement a scalar or a vector quantity? Give one reason for your answer.