A Steel rod of cross-sectional area 1m² is acted upon by forces as shown in the Fig. Determine the total elongation of the bar. Take Y = 2.0 ×10¹¹N m⁻².
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A Steel rod of cross-sectional area 1m² is acted upon by forces as shown in the Fig. Determine the total elongation of the bar. Take Y = 2.0 ×10¹¹N m⁻².

G1 Physics · Accepted Answer

Use stress σ=F/A, strain ε=ΔL/L and Young's modulus Y=σ/ε. For a uniform segment, ΔL=FL/(AY); for thermal restraint, thermal strain αΔT produces stress YαΔT. Evaluating the given data/statements gives A: 1.3 μm. Therefore the correct answer is A.