Question

Calculate the work done in stretching a steel wire of length 2m and cross sectional area 0.0225mm² when a load of 100 N is slowly applied to its free end. [Young’s modulus of steel= 2 × 10¹¹ N/m²]

Answer 1

Given. L = 2m, F = 100 N,

A = 0.0225 mm² = 2.25 × 10^-8 m²,

Y = 2 × 10^-11 N/m²,

To find : Work (W)

Formula : W = 1/2 × F × l

Claculation :

= antilog [log 10 – log 4.5] 

= antilog [1.0000 – 0.6532 ] 

= antilog [0.3468] 

∴ W = 2.222 J

The work done in stretching the steel wire is 2.222 J.