IBM Ponder This #021 · January 2000

On an airless planet, a fly ball is hit directly toward an outfielder. The fielder can observe the changing angle the ball makes with the horizon, but cannot judge changes in distance from the ball's apparent size. There is no apparent lateral motion.

How can the fielder decide whether to move forward or backward in order to catch the ball?

Solution

Best opened after a real attempt

Solution

To be added.