Starting from rest a particle is first accelerated for time t1 with constant acceleration a1 and then stops in time t2 with constant retardation a2 . Let v1 be the average velocity in this case and s1 the total displacement. In the second case it is accelerating for the same time t1 with constant acceleration 2a1 and come to rest with constant retardation a2 in time t3 . If v2 is the average velocity in this case and s2 the total displacement, then
a. v2=2v1
b. 2v1<v2<4v1
c. s2=2s1
d. 2s1<s2<4s1