Question

The length of a spring varies directly with the mass of an object that is attached to it. When a 30-gram object is attached the
spring stretches 9 centimeters. Which equation relates the mass of the object, m, and the length of the spring, s?
m
10
10
S.
m
3
0 m
ma
30

Answer 1

We have been given that the length (s) of a spring varies directly with me mass (m) of an object. We are asked to find the equation that represents the relation, when a 30-gram object is attached the  spring stretches 9 centimeters.

We know that two directly proportional quantities are in form $y=kx$, where y is directly proportional to x and k is constant of proportionality.

Let us find constant of proportionality for our relation.

$s=k\cdot m$

$9=k\cdot 30$

$\frac{9}{30}=\frac{k\cdot 30}{30}$

$\frac{3}{10}=k$

$0.3=k$

Therefore, our required equation would be $s=0.30m$.