1. The problem statement, all variables and given/known data At t = 0, a particle moving in the xy plane with constant acceleration has a velocity of vi = (3.00 i - 2.00 j) m/s and is at the origin. At t = 2.50 s, the particle's velocity is v = (6.10 i + 4.90 j) m/s. (a) Find the acceleration of the particle at any time t. (Use t, i, and j as necessary.) 2. Relevant equations avg. acceleration = change in Velocity / Change in time 3. The attempt at a solution I subtracted the two vectors (vf -vi) and this is what I got for my equation to find acceleration of the particle at any time t. avg accel. = (3.10i+6.90j)/t but when I entered this into the web page I got the answer wrong. Any suggestion would be appreciated.