Answer:
Option E
Explanation:
All the given statements are true except the velocity gradients normal to the flow direction are small since these are not normally small. It's true that viscous effects are present only inside the boundary layer and the fluid velocity equals the free stream velocity at the edge of the boundary layer. Moreover, Reynolds number is greater than unity and the fluid velocity is zero at the surface of the object.
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
A broken yellow line on the pavement tells that the adjacent lane is traveling in the opposite direction and passing is permitted.
A broken white line on the pavement show that the adjacent lane is traveling in the same direction and passing is permitted.
<h3>What does pavement markings show?</h3>
Pavement markings are known to be tools that are used to pass infor or messages to roadway users.
Note that they tell the part of the road that one need to use, give information about conditions ahead, and others
Note that A broken yellow line on the pavement tells that the adjacent lane is traveling in the opposite direction and passing is permitted.
Learn more about pavement markings from
brainly.com/question/10179521
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Q:What velocity does the boy attain if he throws the bricks one at a time?
Answer:Linear velocity since it moves back and firth and does not rotate like angular velocity.
