Answer: Dampness or moisture introduces hydrogen into the weld, which causes cracking when some metals are welded.
Explanation:
<em>This moisture (hydrogen) is a major cause of weld cracking and porosity. </em>
Explanation:
The correct answers to the fill in the blanks would be;
1. Viscoelastic stress relaxation refers to scenarios for which the stress applied to a polymer must decay over time in order to maintain a constant strain. Otherwise, over time, the polymer chains will slip and slide past one another in response to a constant applied load and the strain will increase (in magnitude).
2. Viscoelastic creep refers to scenarios for which a polymer will permanently flow over time in response a constant applied stress.
The polymer whose properties have been mentioned above is commonly known as Kevlar.
It is mostly used in high-strength fabrics and its properties are because of several hydrogen bonds between polymer molecules.
Answer:
diesel engine
Explanation:
because diesel is stronger than petrol
Answer:
diameter is 14 mm
Explanation:
given data
power = 15 kW
rotation N = 1750 rpm
factor of safety = 3
to find out
minimum diameter
solution
we will apply here power formula to find T that is
power = 2π×N×T / 60 .................1
put here value
15 ×
= 2π×1750×T / 60
so
T = 81.84 Nm
and
torsion = T / Z ..........2
here Z is section modulus i.e = πd³/ 16
so from equation 2
torsion = 81.84 / πd³/ 16
so torsion = 416.75 / / d³ .................3
so from shear stress theory
torsion = σy / factor of safety
so here σy = 530 for 1020 steel
so
torsion = σy / factor of safety
416.75 / d³ = 530 ×
/ 3
so d = 0.0133 m
so diameter is 14 mm
Answer:
a)
, b)
,
,
, c)
,
,
, 
Explanation:
a) The total number of users that can be accomodated in the system is:


b) The length of the side of each cell is:


Minimum time for traversing a cell is:



The maximum time for traversing a cell is:


The approximate time is giving by the average of minimum and maximum times:


c) The total number of users that can be accomodated in the system is:


The length of each side of the cell is:


Minimum time for traversing a cell is:



The maximum time for traversing a cell is:


The approximate time is giving by the average of minimum and maximum times:

