posted by Vance Reed .
Hooke's Law. The distance d when a spring is stretched by a hanging object varies directly as the weight w of the object. If the distance is 64cm when the weight is 3kg, what is the distance when the wight is 9kg?
Use the first set of data to find k, k=W/d
Then, use that k to find the second distance...
distance= k * w
I know you are in a math class, and the teacher probably doesn't know, but kg is not a unit of weight, but of mass. Mass only has weight under the influence of gravity, and varies with location and altitude.