#format jsmath
= Kevlar =
(Kevlar is a trademark of !DuPont)

|| {{attachment:kevlar.jpg}} || {{attachment:stephanie-kwolek.kevlar.jpg}} || Kevlar is a high strength aramid fiber invented by Stephanie Kwolek in the 1960s, and sold by !DuPont since 1971 ||

||<-3> '''Kevlar 49 Properties'''   ||<-2>'''Kevlar in matrix, WAG'''  ||
||       3 || GPa     || breaking strength         ||     2 || GPa     ||
||     124 || GPa     || tensile modulus           ||    82 || GPa     ||
||    1.44 || g/cm^3^ || density                   ||   1.5 || g/cm^3^ ||
||    2.08 || MYuri   || specific strength         ||   1.3 || MYuri   ||
||     9.3 || km/s    || longitudinal speed        ||     7 || km/s    ||
||     212 || km      || 9.8 m/s² support length   ||   130 || km      ||
||     3.6 || %       || max strain at break       ||
||     2.4 || %       || strength/tensile          ||
||     1.4 || km/s    || max transverse speed      ||
||     110 || $/kg    || cost (old citation)       ||

 . A 14 km/s loop increases speed by 69 m/s over a 100 km descent.  That is a stretch of 0.49%, 20% of the strength/tensile ratio
 . A 12 km/s loop increases speed by 80 m/s over a 100 km descent.  That is a stretch of 0.67%, 28% of the strength/tensile ratio

$ \large stretch ~ \approx ~ { \Large { { \mu ( r_2 - r_1 ) } \over { V^2 r_2 r_1 } } ~ \approx ~  { 9.64 ~ km^2/s^2 \over V^2 } } $ 
 
Kevlar [[attachment:KEVLAR_Technical_Guide.pdf | Technical Guide]] downloaded from !DuPont.  Properties pdf page 9, thermal page 120