A large plate is fabricated from a steel alloy that has a plane strain fracture toughness of 82.4MPa(75.0ksi). If the plate is exposed to a tensile stress of 345 MPa (50,000 psi) during service use, determine the minimum length of a surface crack that will lead to fracture. Assume a value of 1.0 for Y.

Given:

plane strain fracture toughness=

tensile stress =

we know the formula:

Rearranging the formula

inserting values in formula

simplifying we get

neither accurate nor precise.

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft