Answer:

Explanation:
From the question we are told that:
Plane strain fracture toughness of 
Y value 
Stress level of
Generally the equation for length of a surface crack is mathematically given by



Therefore
in mm

Answer:
Explanation:
Given:
Tooth Number, N = 24
Diametral pitch pd = 12
pitch diameter, d = N/pd = 24/12 = 2in
circular pitch, pc = π/pd = 3.142/12 = 0.2618in
Addendum, a = 1/pd = 1/12 =0.08333in
Dedendum, b = 1.25/pd = 0.10417in
Tooth thickness, t = 0.5pc = 0,5 * 0.2618 = 0.1309in
Clearance, c = 0.25/pd = 0.25/12 = 0.02083in
Answer: At 520 feet between the piers, the center arch of Eads Bridge was the longest rigid span ever built at the time of its construction (only a few suspension bridges had longer spans).
Explanation: