The tower crane is used to hoist a 2-Mg load upward at a constant velocity. The 1.5-Mg jib BD and 0.50Mg jib BC have centers of mass at G1 and G2, respectively. Determine the required mass of the counterweight C so that the resultant moment produced by the load and the weight of the tower cran jibs about point A is zero. The center of mass for the counterweight is located at G3.