Question

A mass of 15 grams stretches a spring

5 centimeters. If the distance this spring is
stretched varies directly with the attached
mass, what mass will stretch the spring
12 centimeters?

Answer 1

36 grams mass will stretch the spring 12 centimeters.

Explanation:

Here, Distance of the spring ∝ The Mass attached

or D = k M ( for some arbitrary constant k )

Now, for m = 15 g, D = 5 centimeters

So, here 5 = k(15)

or,
`k = (5)/(15)  = (1)/(3)`

⇒ For D= 12 cm , D = k M

⇒
`12 = (1)/(3) * M\\M = 12 * 3 = 36`

or, M = 36 grams

Hence, 36 grams mass will stretch the spring 12 centimeters.