Two horizontal forces, P and Q, are acting on a block that is placed on a table. We know that P is directed to the left but the direction of Q is unknown; it could either be directed to the right or to left. The object moves along the x-axis. Assume there is no friction between the object and the table. Here P = -5.7 N and the mass of the block is 3.0 kg. P (a) What is the magnitudeand direction of Q (in N) when the block moves with constant velocity? (Indicate the direction with the sign of your answer.) N (b) What is the magnitude and direction of Q (in N) when the acceleration of the block is +4.0 m/s. (Indicate the direction with the sign of your answer.) N (c) Find the magnitude and direction of Q (in N) when the acceleration of the block is -4.0 m/s. (Indicate the direction with the sign of your answer.) N