Answer
a). $15.31kg$
b). $5.1kg$
Work Step by Step
a). $m_{1}g=kx_{1}$
$m_{1}=\frac{kx_{1}}{g}=\frac{2.5\times1000\times0.06}{9.8}=15.31kg$
b). $m_{2}g=k(x_{2}-x_{1})$
$m_{2}=\frac{k(x_{2}-x_{1})}{g}=\frac{2.5\times1000\times(0.08-0.06)}{9.8}=5.1kg$
