If the outer radius is halved while torque and the polar moment of inertia remain constant, how does the shear stress change?

Prepare for the NOCTI Pre-Engineering Exam. Utilize practice questions and detailed explanations to sharpen your engineering skills. Ensure your success with comprehensive study guides!

Multiple Choice

If the outer radius is halved while torque and the polar moment of inertia remain constant, how does the shear stress change?

Explanation:
When a shaft is under torsion, the shear stress at the outer surface is given by tau = T * c / J, where c is the outer radius and J is the polar moment of inertia. If torque and J stay the same but the outer radius is halved, the only change is c, which halves. Therefore tau becomes (T * (c/2)) / J = (1/2) * (T * c / J). So the shear stress is reduced by half.

When a shaft is under torsion, the shear stress at the outer surface is given by tau = T * c / J, where c is the outer radius and J is the polar moment of inertia. If torque and J stay the same but the outer radius is halved, the only change is c, which halves. Therefore tau becomes (T * (c/2)) / J = (1/2) * (T * c / J). So the shear stress is reduced by half.

Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy