A vertical metal cylinder of radius 2 cm and length 2 m is fixed at the lower end and a load of 100 kg is put on it. Find (a) the stress (b) the strain and (c) the compression of the cylinder. Young modulus of the metal = 2×1011Nm−2.
r = 2 cm
⇒A=πr2=4πcm2
= 4π×10−4m2
L= 2 m
m = 100 kg
Y = 2×1011N/m2
(a) ρ=stress=mgA
= (100×10)(4π×10−4)
=7.96×105N/m2
(b) c = strain
= ρY=(97.96×105)(2×1011)
= 4×10−6
(c) Compression ΔL=eL
= 4×10−6×2=8×10−6m