1. The problem statement, all variables and given/known data 1. At t = 0, a particle leaves the origin with a velocity of 9.0 m/s in the positive y direction and moves in the xy plane with a constant acceleration of (2.0i - 4.0j) m/s2. At the instant the x coordinate of the particle is 15 m, what is the speed of the particle? 2. A particle starts from the origin at t = 0 with a velocity of 6.0 m/s and moves in the xy plane with a constant acceleration of (-2.0 + 4.0 ) m/s2. At the instant the particle achieves its maximum positive x coordinate, how far is it from the origin? 2. Relevant equations rf = ri + vt + 1/2at^2 vf = vi + at 3. The attempt at a solution 1. rf = ri + vt + 1/2at^2 t = 2.25 [seconds] vf = (9j) + [2i - 4j)t Sub t into there and i get 4 m/s But the answer is: 10 m/s 2. v(initial)=6i m/s v(final)=? a= (-2i + 4j) m/s^2 starts at coordinate (0,0) need to find max x point rf = 6i + [-1i + 2j]t^2 vf = vi + at How do i find t if i don't have final velocity? Answer is: 20m.