An object’s velocity as a function of time is given by v(t)=bt−ct3, where b and c are positive constants with appropriate units.

A. If the object starts at x=0 at time t=0, find an expression for the time when it’s again at x=0. Express answer in terms of b & c.

B. Find an expression for its acceleration at that time.
Express your answer in terms of variables b and c.