1. The problem statement, all variables and given/known data The velocity of an object moving along the x-axis is given by Vx = (2.0t-t2)m/s. Initially (at t=0), the object was at the origin. a) Determine the object's acceleration at t=3.0s. b) Find the object's position at t=3.0s c) Calculate the object's maximum positive displacement from the origin. 2. Relevant equations a = dv/dt xf = xi + vxit + (1/2)axt2 vxf2 = vxi2 + 2ax 3. The attempt at a solution a) To get an equation for acceleration, ax = dv/dt = d/dt (2.0-2t) = 2.0 - 2(3.0s) = -4.0 m/s2 b) xf = xi + vxit + 1/2axt2 = (0 m) + (0 m/s)(3.0 s) + 1/2 (-4.0 m/s2)(3.0s)2 = -18.0 m c) delta x = [vxf2 - vxi2] / [2ax] = [2.0 (3.0s) - (3.0s)2]2 - [0 m/s] / [2 (-4.0 m/s2)] = -1.1 m First of all, I'm not sure if I've done the derivation for the accleration equation correctly. Also, question c) asks for maximum POSITIVE displacement but I keep getting a negative value. I'm not sure where I'm going wrong!