Answer:
0.024 m = 24.07 mm
Explanation:
1) Notation
= tensile stress = 200 Mpa
= plane strain fracture toughness= 55 Mpa
= length of a surface crack (Variable of interest)
2) Definition and Formulas
The Tensile strength is the ability of a material to withstand a pulling force. It is customarily measured in units (F/A), like the pressure. Is an important concept in engineering, especially in the fields of materials and structural engineering.
By definition we have the following formula for the tensile stress:
(1)
We are interested on the minimum length of a surface that will lead to a fracture, so we need to solve for
Multiplying both sides of equation (1) by
(2)
Sequaring both sides of equation (2):
(3)
Dividing both sides by we got:
(4)
Replacing the values into equation (4) we got:
3) Final solution
So the minimum length of a surface crack that will lead to fracture, would be 24.07 mm or more.
Given:
diameter of sphere, d = 6 inches
radius of sphere, r = = 3 inches
density, = 493 lbm/
S.G = 1.0027
g = 9.8 m/ = 386.22 inch/
Solution:
Using the formula for terminal velocity,
= (1)
where,
V = volume of sphere
= drag coefficient
Now,
Surface area of sphere, A =
Volume of sphere, V =
Using the above formulae in eqn (1):
=
=
=
Therefore, terminal velcity is given by:
= inch/sec