A record turntable is rotating at $331/3$ rev$/$min$.$ A watermelon seed is on the turntable $4\mathrm{.}3$ cm from the axis of rotation. $($a$)$ Calculate the acceleration of the seed, assuming that it does not slip. $($b$)$ What is the minimum value of the coefficient of static friction between the seed and the turntable if the seed is not to slip?$($c$)$ Suppose that the turntable achieves its angular acceleration for $0\mathrm{.}15$s$.$ Calculate the minimum coefficient of static friction required for the seed not to slip during the acceleration period.