Question

An elastic string of length is elastically stretched through a length e by a force F, the area of cross-section of the string is A while its Young Modulus is E. which of the following expressions is correct? *
F= EAe/l
F=EAl/e
F= Eel/A
F=EAe

Answer 1

E=stress /strain

Stress=Force/area=F/A

Strain=∆l/l=e/l

E=F×l/A×e

F=E×A×e/l

I hope this helps