The smallest angular velocity is 17.7rad/s
Explanation:
We know,
[tex]T = \frac{Tr}{J}[/tex]
For solid shaft, [tex]J = \frac{\pi }{2} r^4[/tex]
For hollow shaft, [tex]J = \frac{\pi }{2} (r_o^4 - r_i^4)[/tex]
Therefore,
[tex]T_m_a_x = \frac{Tr}{J} \\\\[/tex]
[tex]80 X 10^6 = \frac{T (0.03)}{\frac{\pi }{2}(0.03)^4 } \\\\T = 3392.92 Nm\\[/tex]
We know,
P = Tω
[tex]w = \frac{P}{T} \\\\w = \frac{60 X 10^3}{3392.92} \\\\w = 17.7rad/s[/tex]
Thus, the smallest angular velocity is 17.7rad/s