1. The problem statement, all variables and given/known data The velocity of a 4 kg particle is given by v = (3ti + 6t^2j ) m/s, with time t in seconds. At the instant the net force on the particle has a magnitude of 38 N, what are the direction (relative to the positive direction of the x axis) of (a) the net force and (b) the particle's direction of travel? 2. Relevant equations 3. The attempt at a solution I took the second derivative of V to get the acceleration which is 3(i) + 12t(j). What should my next step be?