The maximum elongation of a steel wire of 1 m length if the elastic limit of steel and its Young's modulus are respectively 8×10⁸ N m⁻² and 2×10¹¹ N m⁻², is:

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(1) 4 mm. Given: L=1 m, elastic limit σₘₐₓ=8×10⁸ N m⁻², Y=2×10¹¹ N m⁻². Idea: the wire stays elastic up to the elastic limit, so the largest strain it can carry is the elastic limit divided by Young's modulus. Y=σ/(strain), so strainₘₐₓ=(σₘₐₓ)/Y. strainₘₐₓ=(8×10⁸)/(2×10¹¹)=4×10⁻³ Δ L=strain× L=4×10⁻³×1=4×10⁻³ m Δ L=4 mm

The maximum elongation of a steel wire of 1 m length if the elastic limit of steel and its Young's modulus are respectively 8×10⁸ N m⁻² and 2×10¹¹ N m⁻², is:

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