Here k = 147 Nm-1
In figure (a), the effective spring constant,
k1 = k + k = 2k = 2 × 147 = 294 Nm-1
∴ Elongation in the spring,
y1 = \(\frac{mg}{k}=\frac{5\times9.8}{294}=\frac{1}{6}m\)
In figure (b), the effective spring constant,
\(k_2=\frac{k\times k}{k\times k}=\frac{k}{2}\)
= \(\frac{147}{2}\)m-1
∴ Total elongation in the spring
\(y_2=\frac{5\times 9.8\times 2}{147}=\frac{2}{3}\) m
In figure (c), the effective constant,
k= 147 Nm-1
∴ Elongation in the spring,
y3 = \(\frac{5\times 9.8}{147}=\frac{1}{3}\) m.