This question is incomplete, the complete question is;
For a steel alloy it has been determined that a carburizing heat treatment of 11.3 h duration at Temperature T1 will raise the carbon concentration to 0.44 wt% at a point 1.8 mm from the surface. A separate experiment is performed at T2 that doubles the diffusion coefficient for carbon in steel.
Estimate the time necessary to achieve the same concentration at a 4.9 mm position for an identical steel and at the same carburizing temperature T2.
Answer:
the required time to achieve the same concentration at a 4.9 is 83.733 hrs
Explanation:
Given the data in the question;
treatment time t₁ = 11.3 hours
Carbon concentration = 0.444 wt%
thickness at surface x₁ = 1.8 mm = 0.0018 m
thickness at identical steel x₂ = 4.9 mm = 0.0049 m
Now, Using Fick's second law inform of diffusion
/ Dt = constant
where D is constant
then
/ t = constant
/ t₁ =
/ t₂
t₂ = t₁
t₂ = t₁
/ 
t₂ = (
/
)t₁
t₂ =
/
× t₁
so we substitute
t₂ =
0.0049 / 0.0018
× 11.3 hrs
t₂ = 7.41 × 11.3 hrs
t₂ = 83.733 hrs
Therefore, the required time to achieve the same concentration at a 4.9 is 83.733 hrs
Answer:
True
Explanation:
Dual home host - it is referred to as the firewall that is incorporated with two or more networks. out of these two networks, one is assigned to the internal network and the other is for the network. The main purpose of the dual-homed host is to ensure that no Internet protocol traffic is induced between both the network.
The most simple example of a dual-homed host is a computing motherboard that is provided with two network interfaces.
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:


The pilot valve and spark igniter are energized, the pilot flame is proved, and then the main gas valve is energized.