If a compressed spring is completely dissolved in acid, the elastic potential energy (E.P.E) of the spring will be converted into other forms of energy such as thermal energy and sound energy. This is because the acid will react with the material of the spring, causing it to break down and release its stored energy.
The conversion of E.P.E into thermal energy can be explained by the law of conservation of energy. This law states that energy cannot be created or destroyed, but it can be converted from one form to another. In this case, the energy stored in the compressed spring is being converted into thermal energy as the chemical reaction between the acid and the spring's material produces heat.
Additionally, the dissolution of the spring in acid will also result in the release of sound energy. As the spring breaks down and reacts with the acid, it may produce a popping or hissing sound due to the rapid release of energy.
In conclusion, the E.P.E of a compressed spring will be converted into thermal and sound energy when it is dissolved in acid. This is due to the chemical reaction between the two substances, which causes the spring to break down and release its stored energy.