4.2 Related Rates (#differentiation) Solve the following problems using the related rates method. (Adapted from Stewart) (a) A spherical iron ball 6 cm in diameter is coated with a layer of ice with uniform thickness. If the ice melts at a rate of 25 cm³/min how fast is the thickness of the ice decreasing when it is 4 cm thick? 4/n4.2 Related Rates (#differentiation) Solve the following problems using the related rates method. (Adapted from Stewart) (a) A spherical iron ball 6 cm in diameter is coated with a layer of ice with uniform thickness. If the ice melts at a rate of 25 cm³/min how fast is the thickness of the ice decreasing when it is 4 cm thick? 4

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