Question

A uniform bar of length L; cross-section area A and Young’s modulus Y is acted upon by forces as shown. If elongation in the bar is $\frac{\text{NL}}{\text{AY}}$; then N is ___.

Answer 1

$\Delta \text{L}=\frac{{\text{F}}_{\text{av}}\text{L}}{\text{AY}}$

$=\frac{\left(\frac{4+6}{2}\right)\text{L}}{\text{AY}}=\frac{5\text{L}}{\text{AY}}$