1. The problem statement, all variables and given/known data Questions 19 and 20 refer to the following information A particle of mass 2.00 kg moves under a force given by F~ = −(8.00 N/m)(i + j) where i and j are unit vectors in the x and y directions. The particle is placed at the origin with an initial velocity v = (3.00 m/s)i + (4.00 m/s)j 19. After how much time will the particle ﬁrst return to the origin? (A) 0.785 s (B) 1.26 s (C) 1.57 s (D) 2.00 s (E) 3.14 s The correct answer is C 20. What is the maximum distance between the particle and the origin? (A) 2.00 m (B) 2.50 m (C) 3.50 m (D) 5.00 m (E) 7.00 m The correct answer is B 2. Relevant equations F = ma 3. The attempt at a solution I keep messing up somewhere. If f = -8i - 8j a = -4i - 4j Antidifferentiate: v = (-4t + 3)i + (-4t+4)j r = (-2t^2 + 3t)i +(-2t^2 + 4t)j I can't find an answer that is one of the above choices.