A metal wire of length $l$ and cross-sectional area $A$ is secured at one end. When a mass $m$ is attached to the free end, the wire stretches by a distance $e$. What is an expression for the Young modulus $E$ of the metal?
- A$E=\frac{ml}{Ae}$
- B$E=\frac{mgl}{Ae}$
- C$E=\frac{me}{Al}$
- D$E=\frac{mge}{Al}$