The figure shows an initially stationary block of mass m on a floor. A force of magnitude 0.500 mg is then applied at upward angle θ = 15.0∘. What is the magnitude of the acceleration of the block across the floor if the friction coefficients are (a) static = 0.600 and kinetic = 0.500 and (b) static = 0.400 and kinetic = 0.300?