Wetzel

Math 140

2.6 – Related Rates

Related Rates –         Differentiation with respect to t

            def.- rates of change of two or more related variables changing over time.

Ex.:

1.)  A pebble is dropped into a calm pond of water, causing ripples in the form of concentric circles.  The radius, r, of the outer ripple is increasing at a constant rate of 1 foot per second.  When the radius is 4 feet, at what rate is the total area A of the disturbed water changing?

2.)  The formula for the volume of a cone is .  Find the rate of change of the volume if  is 2 inches per minute and  when (a) r = 6 inches and (b) r = 24 inches.

HW:  p.154 #1, 3, 15, 19, 23, 27, 33, 35