Figure 6-24 shows an initially stationary block of mass m on a floor. A force of magnitude 0.400mg is then applied at upward angle = 23.

shows an initially stationary block of mass m on a floor. A force of magnitude 0.400mg is then applied at upward angle θ = 23°. What is the magnitude of the acceleration of the block across the floor if (a)μs = 0.600 and μk = 0.500 and (b)μs = 0.400 and μk = 0.300?