Finding the spring constant as shown, spring 3, which has an unknown spring constant k3, replaces spring 2. the mass of the weight and pulley are unchanged: m=5.8 kg and mp=1.7 kg . however, because of the different spring constant the distance the pulley hangs below the ceiling is now, h=112.5 cm . the unloaded length of spring 3 is ℓ′3=27.5 cm ; after hanging the mass and pulley, the spring's length is ℓ3=34.5 cm . determine the spring constant of spring 3, k3.