Figure shows the strain-stress curve for a given material. What are (a) Young's modulus and (b) approximate yield strength for this material ?

Explanation

(a) From the given graph for stress `150 xx 10 ^(6) Nm ^(-2)` corresponds strain is `0.002`
`therefore` Young.s modulus
,= slope of graph stress `to` strain
`therefore` Young.s modulus
`Y= ("Stress")/("Strain") =(150 xx 10 ^(6))/(0.002)`
`therefore Y=7.5 xx 10 ^(8) Nm ^(-2)`
(b) From graphs the yield strength of a material is the maximum stress,
`= 300 xx 10 ^(6) Nm ^(-2)`
`= 3 xx 10 ^(8) Nm ^(-2)`
Really the yield strength is slightly less than `3 xx 10 ^(8) N m ^(-2)`