The displacement of a particle moving along the x–axis is given by x(t)=2t2+3t+1 (where x is in metres and t in seconds).
(i) Calculate the average velocity of the particle between t=1s and t=4s.
(ii) Find the instantaneous velocity at t=2.5s.
(iii) State whether the motion is uniform or non-uniform, giving a brief reason based on your results.