Given, Kinetic energy k=2t2
On differentiating, we get
dkdt=4t
⇒dk=4tdt=F.ds
⇒4tdt=aTds (since mass is 1 kg)
Integrating,
t∫04tdt=v∫0vdv
⇒4t22+c=v22
Using the given condition v=0 at t=0, we get c=0
⇒v=2t
∴ At t=2 sv=4 m/s
So, centripetal acceleration
ac=v2R=428=2 m/s2