1. The problem statement, all variables and given/known data The position of an object traveling in a straight line at time t is given by s(t) = (2/3)t^2 + 4t^2 + 6t + 2. What's the displacement after 3 seconds? 2. Relevant equations Displacement is final position minus initial position. 3. The attempt at a solution Displacement at 3 seconds is s(3) - s(0). s(0) = 2. Note the constant term! s(3) = 18 - 36 + 18 + 2. s(3) - s(0) = 0. Interestingly enough, my key claims displacement is simply s(3). I'm guessing this is an error (and not on my part)!