### Home > CALC > Chapter 10 > Lesson 10.1.4 > Problem10-30

10-30.

After Barry hit a home run, Sammy leaves 1st base for 2nd traveling at 12 feet per second. At the same time, Mark left 2nd base for 3rd traveling at 16 feet per second. Assuming that the bases are 90 feet apart, at what time after Barry hit the ball was the distance between Sammy and Mark at a minimum? What was the distance between them at that time? Homework Help ✎

Sammy's distance is the horizontal leg of a right triangle. It is decreasing with time.
Write an expression for Sammy's distance (from second base).

Mark's distance is the vertictal leg of a right triangle. It is increasing with time.
Write an expression for Mark's distance (from third base).

Use the Pythagorean Theorem to write an equation for the distance between Sammy and Mark.

Differentiate your equation and set it equal to 0 to solve for the time when the distance between Sammy and Mark is a minimum.