1. The problem statement, all variables and given/known data A 0.35 kg particle moves in an xy plane according to x(t) = - 11 + 1 t - 6 t3 and y(t) = 19 + 3 t - 8 t2, with x and y in meters and t in seconds. At t = 0.7 s, what are (a) the magnitude and (b) the angle (within (-180°, 180°] interval relative to the positive direction of the x axis) of the net force on the particle, and (c) what is the angle of the particle's direction of travel? 2. Relevant equations Fx=m(ax) Fy=m(ay) 3. The attempt at a solution I got the first part right by taking the second derivative of each plane and applying it to the equations. (ax)= dvx/dt = -36t m/s^2 (ay) = dvy/dt = -16 m/s^2 and by applying the relevant equations Fx= -8.82 Fy= -5.6 By using Pythagoras theorem I found that the net force to be Fnet= 10.448 Which is right. After drawing a picture in part b my attempt to solve was tan^-1(theta)= Fy/Fx Which is tan^-1(theta) = -5.6/-8.82 theta = 32.41 which I got wrong ___________________________________________ Part C My attempt was applying in the velocity functions of both planes which are Vx= 1-18t^2 Vy= 3-16t and finding that Vx= -7.82 Vy= -8.2 After that tan^-1(theta)= -8.2/-7.82 theta= 46.358 which I also got wrong. Thanks in advance.