A wire of a length 1m and diameter of 0.4mm is hung from a ceiling. Find the extension caused in the wire, by attaching a weight of 100N, if the material of the wire has the Young's modulus E = 200×1011Nm
(a) stressE=strain
Stress = force\area =100crossectionalarea = 100(p4)(8×10−4)2 Pa = Q.1)99× 108Pa
Strain = 99×108200×1011=0.995×10−3 m= 0.995mm~1mm