# Mechanical properties of solids

Young's modulus of bone for tensile is $16× 10^9 N/m^2$ and for compressive is $9 × 10^9 N/m^2$

Why is tensile Young's modulus is more than for compressive? • Do you have a reference for those numbers? They seem to be wrong by several orders of magnitude. You may be confusing tensile and compressive strength with Young's modulus. – alephzero Jan 21 '17 at 13:54
• @alephzero it is given in NCERT textbook of physics, I added screenshot – Fawad Jan 21 '17 at 14:10
• Your post says the Young's modulus is $16 \times 10^7$ but the table says $16 \times 10^9$. That's what was confusing me. But the NCERT tensile strength numbers are 10 times smaller than springer.com/cda/content/document/cda_downloaddocument/… (page 8 of the PDF). – alephzero Jan 21 '17 at 16:11
• @alephzero that was a typo , I just want to know why there is difference for two types – Fawad Jan 21 '17 at 17:31
• – JM97 Mar 5 '17 at 13:12

## 1 Answer

The possible sources for difference are: 1) different sample materials (i.e. different bones studied); 2) different conditions (like water content in the bone etc.); 3) different methods used (e.g. ultrasonic and mechanical results differ).

Other than that, for the same bone type measured with the same technique under same conditions both values should be the same.