Final answer:
The velocity of the particle at t = 3.0 s is 24.6 m/s.
Step-by-step explanation:
The velocity of the particle can be found by taking the derivative of the position function, x(t). In this case, x(t) = At + Bt², so the derivative is v(t) = A + 2Bt. Given that A = -4.3 m/s and B = 4.9 m/s², we can substitute these values into the derivative equation to find the velocity at t = 3.0 s.
Substituting t = 3.0 s, A = -4.3 m/s, and B = 4.9 m/s², we get v(3.0 s) = -4.3 + 2(4.9)(3.0) m/s = 24.6 m/s.
Therefore, the velocity of the particle at t = 3.0 s is 24.6 m/s.