Aspeedboat travels from the dock to the first buoy, a distance of 20 meters, in 18 seconds. it began the trip at a speed of o m/s. by the time it reached the buoy, it was going 10 m/s. what was the average velocity of the boat? a) -3.33 m/s^2 b) -1.11 m/s c) +1.11 m/s d) +3.33 m/s