Bonus Material For Advanced Learners

• Problem of the Day

You are playing catch with a small child and you would like the speed of the ball to be as small as possible when it reaches the child. Every time you move towards the child, the child steps back because he or she does not want to be babied, keeping the distance between the two of you constant. How should you throw the ball to the child so that it reaches the child without bouncing and yet its speed upon reaching the child is minimized?