Step 1: Understanding the Concept:
de Broglie wavelength: \(\lambda = \frac{h}{p}\), where \(p\) is momentum. Kinetic energy \(K = \frac{p^2}{2m}\).
Step 2: Detailed Explanation:
Given \(K = 2E\). So, \(2E = \frac{p^2}{2m} \Rightarrow p^2 = 4mE \Rightarrow p = 2\sqrt{mE}\).
Thus, \(\lambda = \frac{h}{p} = \frac{h}{2\sqrt{mE}}\).
Step 3: Final Answer:
The de Broglie wavelength is \(\frac{h}{2\sqrt{mE}}\).