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Problem 1. (a slight modification of Problem SP5 (on page 79) from our textbook) Two blocks tied together by a horizontal string are being pulled across the table by a horizontal force of 21 N, as shown in the diagram below. The 3 kg block has a 8NV frictional force exerted on it by the table, and the 7 kg block has an 10 - A frictional force acting on it. 3 kg 7 kg 21 N 8 N 10 N Figure 1: Schematic graph for Problem 1. (a) What is the net force acting upon the entire two-block system? (b) What is the acceleration of this system? (c) What force is exerted on the 3 kg block by the connecting string? (Consider only the forces acting upon this block. Its acceleration is the same as that of the entire system.)