The amount of extension in an elastic spring varies directly with the weight hung on it. If a weight of 250 gm produces an extension of 3.5 cm, find the extension produced by the weight of 700 gm.

Explanation

Let `x` cm be the extension produced by the weight of `700` gm.
Since, the amount of extension in an elastic spring varies and the weight hung on it is in direct variation, we get :
`⇒ 250/700= 3.5/x`
`⇒ x×250=3.5×700`
`=>x=9.8`
∴ The required extension will be `9.8` cm.