Question

The amount of extension In an elastic string varies directly as the weight hung on it. If a weight of 150 gm produces an extension of 2.9 cm, then what weight would produce an extension of 17.4 cm ?

Answer 1

150 gm of weight produces an extension 2.9 cm
Let x gm of weight will produce an extension of 17.4 cm
Therefore :
$\begin{array}{ccc}\text{Weight (in gm)}& 150& x\\ \text{Extension (in cm)}& 2.9& 17.4\end{array}$
$\therefore \frac{150}{2.9}=\frac{x}{17.4}\Rightarrow 2.9\times x=150\times 17.4\Rightarrow x=\frac{150\times 17.4}{2.9}\Rightarrow x=\frac{150\times 174\times 10}{29\times 10}=9000$
$\therefore$ Weight = 900 gm