A light spring of constant 157 N/m rests verti- cally on the bottom of a large beaker of water. A 5.64 kg block of
wood of density 646 kg/m3 is connected to the top of the spring and the block-spring system is allowed to come to static equilibrium. What is the elongation ∆L of the spring? The acceleration of gravity is 9.8 m/s2 .
Answer in units of cm.