What mass should be suspended from a spring

Question

What mass should be suspended from a spring of length 24cm and spring constant 4.0kNm^-1 in order for the spring to be stretched to a length of 32cm?

Answer 1

Spring will stretch until upwards spring force k Δx balances the downward weight mg. Δx = 32 - 24 cm = 0.08 m. Weight (9.8 m/s²) m = (4,000 N/m) (0.08 m), mass m = (320 N) / (9.8 m/s²) = 33 kg.