Respuesta :

9514 1404 393

Answer:

  0 mph

Step-by-step explanation:

The slope of the curve in section B is ...

  m = (y2 -y1)/(x2 -x1)

  m = (30 mi - 30 mi)/(6 h -4 h) = (0 mi)(2 h) = 0 mi/h

The rate of change in section B is 0 miles per hour.