Learning Resources

Focus B: Instantaneous Rate of Change

Test yourself (Solution)

Height of water at 0.501 sec.

Average rate of change in height compared to time is the slope of the secant line through these two points:

Since the points are "very close" together, we can use this as an approximation to the slope of the tangent at the point t = 0.5 which is the instantaneous rate of change at that point.

Thus the rate of change in height at 0.5 sec is approximately 1.4 cm/sec.