At one instant a bicyclist is 75 m due east of a park's flagpole, going due south with a speed of 12 m/s. Then, 25 s later, the cyclist is 45 m due north of the flagpole, going due east with a speed of 12 m/s. For the cyclist in this 25 s interval, find each of the following. (a) displacement (b) average velocity (c) average acceleration.