• id: JME-08-N15
• title: Applications and Exam Strategy
• tags: applications, problem-solving, jee-tips

Key applications: (1) Structural engineering — beams are I-shaped to maximize $Y$ effect with minimum material. (2) Bridge cables — high $Y$ steel used for minimal elongation. (3) Rubber in shock absorbers — low $Y$, high elastic strain. (4) Cork stoppers — $\nu \approx 0$ means they don't expand laterally when compressed into the bottle neck.

JEE tips: (1) When two wires are in series, total elongation = sum of individual elongations. (2) When in parallel (same elongation), total force = sum. (3) For a wire under its own weight, use $F_{\text{avg}} = Mg/2$ and effective length $L/2$, giving $\Delta L = MgL/(2AY)$. (4) Always check units — $Y$ in Pa, area in m$^2$, force in N.