Stress = forcearea\frac{\text{force}}{\text{area}}areaforce
Force = weight = y2^22, Area = π\piπr2^22, Diameter = yπ\frac{\text{y}}{\pi}πym ⇒ r = y2π\frac{\text{y}}{2\pi}2πym
Stress = y2π×y2(2π)2\frac{y^2}{\pi \times \frac{y^2}{(2\pi)^2}}π×(2π)2y2y2
= y2πy2×4(π)2\frac{y^2}{\pi y^2} \times 4(\pi)^2πy2y2×4(π)2 = 4π\piπNm−2^{-2}−2
