Assignment:
In Fig.a, a 5.1 kg dog stands on an 21 kg flatboat and is 6.1 m from the shore. He walks 2.1 m on the boat toward shore and then stops. Assuming there is no friction between the boat and the water, find how far the dog is then from the shore? (Hint: See Fig. b. The dog moves leftward; the boat moves rightward; but does the center of mass of the boat + dog system move?)
