That means that its velocity at any time t >= 0 is v(t) = integral of a(t) = 24t2/2 + 14t + v(0) = 12t2 + 14t + 17, and its position at any time t >= 0 is s(t) = integral of v(t) = 12t3/3 + 14t2/2 + 17t + s(0) = 4t3 + 7t2 + 17t + 13, so the position of the particle at time t = 5 is the following:
s(5) = 4*53 + 7*52 + 17*5 + 13 = 4*125 + 7*25 + 85 + 13 = 500 + 175 + 98 = 773.