The formula to calculate the Initial Elastic Potential Energy (PEi) is:
\[ PEi = PEf - f \cdot x \]
Where:
Let's say the final elastic potential energy (PEf) is 50 Joules, the spring constant (f) is 200 N/m, and the change in position (x) is 0.1 meters. Using the formula:
\[ PEi = 50 - (200 \times 0.1) \]
We get:
\[ PEi = 50 - 20 = 30 \, \text{J} \]
So, the initial elastic potential energy is 30 Joules.