Step 1: Recall the formula for energy.
Energy is given by the formula:
\[
E = \text{Force} \times \text{Distance}
\]
Step 2: Effect of doubling force and length.
If both force and length are doubled, the energy will change as follows:
\[
E' = 2 \times 2 = 4
\]
So, the new energy will be 4 times the original energy.