(III) A 4.0-kg block is stacked on top of a 12.0-kg block, which is accelerating along a horizontal table at a = 5.2m/s² (Fig. 5–43). Let μₖ = μₛ = μ . <IMAGE>
(c) If μ is only half this minimum value, what is the acceleration of the 4.0-kg block with respect to the 12.0-kg block?