Question

A 0.57-kg block is hung from and stretches a spring that is attached to the ceiling. A second block is attached to the first one, and the amount that the spring stretches from its unstrained length increases by a factor of 5. What is the mass of the second block?

Answer 1

Answer 2

$\textit{For a spring F=-kx}$

$\textit{where x is the stretch.}$

$5kx=-5F$

$\textit{So the force got 5 times. So the mass is 4 times heavier.}$

$\textit{The mass is }4\times 0.57=2.28kg$