Solution to Problem 345 | Helical Springs

Problem 345
A helical spring is fabricated by wrapping wire 3/4 in. in diameter around a forming cylinder 8 in. in diameter. Compute the number of turns required to permit an elongation of 4 in. without exceeding a shearing stress of 18 ksi. Use Eq. (3-9) and G = 12 × 106 psi.
 

Solution 345

How to determine po the proper formula for shear stress if hindi given yung gagamiting formula po?