# If the length of a 47 cm spring increases to 57 cm when a 8 kg weight is hanging from it, what is the spring's constant?

Jun 15, 2017

The spring constant is $= 784 k g {s}^{-} 2$

#### Explanation:

The force is $F = m g = 8 g N$

The extension is $x = 0.57 - 0.47 = 0.1 m$

The spring constant is

$k = \frac{F}{e} = \frac{8 g}{0.1} = 784 k g {s}^{-} 2$