12. Two lifeguards pull on ropes attached to a raft If they pull in the same direction, the raft experiences a net external force of 344 N to the right. If they pull in opposite directions, the raft experiences a net external force of 106 N to the left a. Draw a free body diagram representing the raft for each situation b. Determine the force exerted by each lifeguard on the raft; disregard any other forces acting on the raft. (119 N, 225 N)