# If the length of a 37 cm spring increases to 77 cm when a 3 kg weight is hanging from it, what is the spring's constant?

Feb 23, 2016

$73.5 N / m$

#### Explanation:

From Hooke's Law, $F = k x$

$\therefore k = \frac{F}{x}$

$= \frac{3 \times 9.8}{0.77 - 0.37}$

$= 73.5 N / m$.