. A copper wire 1.00 mm in diameter is used to support a mass of 6.0 kg. If the wire was stretched by 2.00 mm, what was the original length of the wire?

Question

Y = stress/ strain r= 0.5 mm =5 X 10-4 m e= 2mm or 2 X 10-3
Given :
m = 6 kg F = 60 N
A =π r2 = ( 3.14)( 5 X 10-4) (5 X 10-4) = 78.5 X 10-8 = 7.85 X 10-7 m2

11.6 x 10 10 N/m 2 = 60N/ 7.85 X 10-7 m2
( 2 x 10 -3m)/ L0

11.6 x 10 10 N/m ( 2 x 10 -3m)/ L0 = 60N/ 7.85 X 10-7 m2

L0= 182 m