Answer:
Explanation:
Detailed explanation is done in the attach document.
Answer:

Explanation:
Let consider that velocity profile inside the circular pipe is:

The average speed at
is:


The velocity at the center of the pipe is:


Answer:
c
Explanation:
This is because many things, such as pcs, over heat
Answer:
The hardenability increases with increasing austenite grain size, because the grain boundary area is decreasing. This means that the sites for the nucleation of ferrite and pearlite are being reduced in number, with the result that these transformations are slowed down, and the hardenability is therefore increased.