Distance covered by an object from origin in time t is given by x=t_6t^2+t^3,when the acceleration will be 0 ?

Answer 1

If your equation is :
x= 6t^2 + t^3
Then first order derivative gives velocity that is :
V= 12t + 3t^2
Then second order derivative of x gives acceleration :
A = 12 + 6t
As given a =0
Then 12 + 6t =0 this gives t=(-2)
Negative sign can be ignored if question is mentioned specifically.