Answer:
K = ρL²g
Step-by-step explanation:
Consider L as the length of the raft inside the water when the raft is displaced through additional distance y;
Then:
F = upthrust ( restoring force) = weight of the liquid displaced.
![F = V_(\omega) \rho_(\omega) g= A y \rho_(\omega) g](https://img.qammunity.org/2021/formulas/physics/college/q5tnlm59wn3top7hslh2frx8vm2rqlobmg.png)
where;
A = L²
![\rho_(\omega) = \rho](https://img.qammunity.org/2021/formulas/physics/college/75r5g42pjy5ru0faajhzg11z6bugrpr0v7.png)
F = ky.
Then,
![Ay \rho g = ky](https://img.qammunity.org/2021/formulas/physics/college/e7rh8k7os0vldsf88spmr4tqo10ga63hdz.png)
![L^2y \rho g = ky](https://img.qammunity.org/2021/formulas/physics/college/l7hiqezb0nke3h4j5wqrfuucsidraoamql.png)
Divide both sides by y
K = ρL²g