The coil polarity in a waste-spark system is determined by the direction in which the coil is wound (left-hand rule for conventional current flow)and can’t be changed. For example, if a V-8 engine has a firing order of 18436572 and the number 1 cylinder is on compression, which cylinder will be on the exhaust stroke?
Answer:
0.024 m = 24.07 mm
Explanation:
1) Notation
= tensile stress = 200 Mpa
= plane strain fracture toughness= 55 Mpa![\sqrt{m}](https://tex.z-dn.net/?f=%5Csqrt%7Bm%7D)
= 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 ![\lambda](https://tex.z-dn.net/?f=%5Clambda)
Multiplying both sides of equation (1) by ![Y\sqrt{\pi\lambda}](https://tex.z-dn.net/?f=Y%5Csqrt%7B%5Cpi%5Clambda%7D)
(2)
Sequaring both sides of equation (2):
(3)
Dividing both sides by
we got:
(4)
Replacing the values into equation (4) we got:
![\lambda=\frac{1}{\pi}[\frac{55 Mpa\sqrt{m}}{1.0(200Mpa)}]^2 =0.02407m](https://tex.z-dn.net/?f=%5Clambda%3D%5Cfrac%7B1%7D%7B%5Cpi%7D%5B%5Cfrac%7B55%20Mpa%5Csqrt%7Bm%7D%7D%7B1.0%28200Mpa%29%7D%5D%5E2%20%3D0.02407m)
3) Final solution
So the minimum length of a surface crack that will lead to fracture, would be 24.07 mm or more.
Answer:
4m/s
Explanation:
We know that power supplied by the motor should be equal to the rate at which energy is increased of the mass that is to be hoisted
Mathematically
\
We also know that Power = force x velocity ..................(i)
The force supplied by the motor should be equal to the weight (mg) of the block since we lift the against a force equal to weight of load
=> power = mg x Velocity........(ii)
While hoisting the load at at constant speed only the potential energy of the mass increases
Thus Potential energy = Mass x g x H...................(iii)
where
g = accleration due to gravity (9.81m/s2)
H = Height to which the load is hoisted
Equating equations (ii) and (iii) we get
m x g x v = ![\frac{mgh}{t}](https://tex.z-dn.net/?f=%5Cfrac%7Bmgh%7D%7Bt%7D)
thus we get v = H/t
Applying values we get
v = 6/1.5 = 4m/s
Answer:
Option A - fail/ not fail
Explanation:
For this given problem, if the yield strength is now 45 ksi, using Distortion Energy Theory the material will _fail______ and using the Maximum Shear Stress Theory the material will ___not fail_______