A block of mass M, area of cross-section A and length λ is placed on smooth horizontal floor. Two forces F₁ = 5N and F₂ = 3 N are applied on the block as shown in the figure. If Y is Young's modulus of elasticity of material, then total extension in the length of the block will be
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Question

A block of mass M, area of cross-section A and length λ is placed on smooth horizontal floor. Two forces F₁ = 5N and F₂ = 3 N are applied on the block as shown in the figure. If Y is Young's modulus of elasticity of material, then total extension in the length of the block will be

Options

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 C: 4l/(AY). Therefore the correct answer is C.