position, s = 2t2 - 8t + 6
thus velocity is given as v= ds/dt
differentiating we get, v = 4t - 8
at v = 0,
T = 2 sec
and to find total distance of particle at t = 3sec:
the particle's vlocity changes direction at t =2sec
thus displacement of particle at t= 2 sec,
s1 = -2m
displacement of particle at t = 3sec
s2 = 0
thus displacemnt of particle in last one sec,
s3 = 0-(-2) = 2 m
thus total displacemnt,
s = |s1| + s3 = 4 m