Use the given acceleration function and initial conditions to find the velocity vector v(t), and position vector r(t). Then find the position at time t = 4. a(t) = ei - 6k v(0) = 2i + 5j + k, r(0) = 0 v(t) = (+1) +5 + (1 6t) k r(t) = r(4) = (t + e 1)i + 5j + (1 - 31) K (2 + e)* + 7j* - 55k