Question

A wire of length L and area of cross section A is stretched by a force of magnitude F.It is found that the length of the wire is increased by ∆l.Find 1.Longitudinal stress 2.longitidinal strain 3.Youngs modulus

Answer 1

so the longitudinal stress is equal to change in length to the original length
longitudinal stress =delta l/L

Answer 2

1. Longitudinal Stress
=force/ area=F/A
2. Longitudinal Strain
=change in length/original length= ∆l/L
3. Youngs modulus
=Longitudinal stress/Longitudinal strain= (F/A)/(∆l/L)= FL/A∆l