Starting from rest at a dock, a motorboat on a lake heads north while gaining speed at a constant 2.70 m/s² for 21 s. The boat then heads west and continues for 10.5 s at the speed that it had at 21 s. (a) What is the average velocity of the boat during the 31.5-s trip? (b) What is the average acceleration of the boat during the 31.5-s trip? (c) What is the displacement of the boat during the 31.5-s trip?
