Suppose now that you are at rest relative to the raft standing at the rear end except this time the raft is in the middle of the lake moving at a speed of 4.0 m/s. You now start walking (in the direction the raft's motion) to the front of the raft at a speed of 2.0 m/s relative to the raft. While you are walking, what are your speed and the raft's speed relative to a stationary observer?