Provided information: Initial velocity \( u = 0 \, \text{m/s} \) (car starts from rest)
Acceleration \( a = 3 \, \text{m/s}^2 \)
Time \( t = 5 \, \text{s} \) Applying the first kinematic equation: \[ v = u + at \] With the given values: \[ v = 0 + (3)(5) = 15 \, \text{m/s} \] Therefore, Option (b) is the correct answer.