The dubois formula relates a person's surface area, s, in meters2, to weight, w, in kg, and height, h, in cm, by (a) what is the surface area of a person who weighs 60 kg and is 160 cm tall? (b) the person in part a stays constant height but increases in weight by 0.4 kg/year. at what rate is his surface area increasing when his weight is 64 kg?

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?