Practice Question: Maximum Shear Stress within Shaft

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Solution

Polar moment of inertia can be calculated by:

\[J=  \frac{πr^4}{2}\]
Where,
J = Polar moment of inertia
r = radius of shaft 

\[J=  \frac{π(3)^4}{2}\]

\[J=127.3 \,in^4\]

Maximum shear stress can be found by
\[τ= \frac{ Tr}{J}\]
\[τ=  \frac{120(3)}{127.3}\]

\[τ= 2.83 \,ksi\]
 

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