Answer:
1.24 degrees
Explanation:
The twist angle can be calculated using the following formula for torsion:
[tex]T = \frac{E I \theta}{L}[/tex]
Where [tex]I = \frac{\pi r^4}{2} = \frac{\pi 0.7^4}{2} = 0.377 in^4[/tex] is the polar inertia of the circular cross section.
[tex]1666 = \frac{10^7 * 0.377 \theta}{49} = 76969 \theta [/tex]
[tex]\theta = 1666 / 76969 = 0.0216 rad = 0.0216 * 180 / \pi = 1.24^o[/tex]