A spring balance reads from \( 0 \) to \( 50\text{ kg} \) and its scale length is \( 20\text{ cm} \). A body suspended from this balance oscillates with a period of \( 0.6\text{ s} \). What is the mass of the body?

Force constant \( k = \frac{mg_{\max}}{\Delta l} = \frac{50 \times 9.8}{0.2} = 2450\text{ N m}^{-1} \). Period \( T = 2\pi\sqrt{m/k} \implies m = \frac{T^2 k}{4\pi^2} = \frac{(0.6)^2 \times 2450}{4 \times \pi^2} \approx 22.33\text{ kg} \) (or if using \( g = \pi^2 \), \( m \approx 4.6\text{ kg} \)).