Alan and Brianna are driving their cars along the same straight road with the constant velocities of 33 mph and 63 mph, respectively. Their friend Chris is driving along a different straight road at the constant velocity of 52 mph. (All these velocities are measured relative to Earth.)
During the motion, the distance between Chris and Alan always remains equal to that between Chris and Brianna. Find Chris’s speed relative to Brianna.
The March, April, and May issues of Challenges attracted many submissions from all over the world, marking a great finish of the 2020/21 “season.”
We are pleased to recognize the following contributors:
Juan M. Aguirregabiria (University of the Basque Country, Bilbao, Spain)
Phil Cahill (The SI Organization, Inc., Rosemont, PA)
Norman Derby (Southwestern Oregon Community College, Brookings, OR)
Ashmit Dutta, student (Wayzata High School, Plymouth, MN)
Don Easton (Lacombe, Alberta, Canada)
Supriyo Ghosh (Kolkata, India)
Art Hovey (Galvanized...