68 Dependence of the path traversed by the material poi

68 Dependence of the path traversed by the material point of time given by the equation s = A - Bt + Ct2 + Dt3, where C = 0,2 m / s2, D = 0,1 m / s3. Determine: 1) through a time interval t after the start of the movement acceleration of the body a = 1 m / s2; 2) the average acceleration during this time.