Answer:
Step-by-step explanation:
I'm assuming that the length of the spring is s and the mass of the object is m. If that be the case, the direct variation equation, which a line btw, is
s = km where k is the constant of proportionality. We have to solve for k, the slope of the line, in order to determine the model for this situation.
9 = k(30) so
[tex]k=\frac{9}{30}=\frac{3}{10}[/tex] Now that we know, the slope of the line, we can rewrite the equation with the slope in place:
[tex]s=\frac{3}{10}m[/tex], choice A.