Journal of the Mathematics Council of the Alberta Teachers’ Association
Volume 48 Issue 1, December 2010
62
Gregory V Akulov
Once upon a time three whales were swimming along the north-south shoreline in the ocean near the island. Children at the island lighthouse observed the whales· motion and drew their position-time graphs in Cartesian coordinates. They noticed that intersections of three graphs form an isosceles triangle ( see figure below). If the first whale swam at 7 m/s [N] and the second one at 1 m/s [NJ, what is the velocity of the third whale?
