3. Three tugboats are used to bring a large ship to a pier as shown. Each tugboat exerts a 4000 Ib force pushing toward the large ship. Determine an equivalent force and couple system at point A. Isof Isof looff looff 150 f /so f 100 fA A 2 45 a. Equivalent Force = 6030-3570 Ib Equivalent Moment = -1, 150,000k ft-lb b. Equivalent Force = 5230 i-4370j lb Equivalent Moment = -1, 190,000k ft-lb c. Equivalent Force 6030i-3570j Ib Equivalent Moment = 1, 150,000k ft-lb d. None of the above