Question

I am trying to find torque through shear stress acting on a disk. the book integrates, T = integral of rdF = rt2pirdr... i forgot how you translate into terms of dr properly. how can i type an equation in properly?

Answer 1

\[T=\int\limits_{A}^{}rdF=\int\limits_{A}^{}2\tau 2 \pi r dr\] Can someone explain how we switched to dr please. that tau is = to shear stress \[\tau=Force / Area\]