Question

A spring has a length of 12 inches when a 2-pound weight is attached, and a length of 18 inches when a 5-pound weight is attached. Use rate of change to find the length of the spring when no weights are attached.

(1 point)

Answer 1

Let L be length (in inches) and W weight (in pounds). Slope = (18−12)/(5−2) = 2 in/lb. So L = a + 2W. Using L(2)=12 gives a + 4 = 12 → a = 8. Thus L(0) = 8 inches.