Answer:
(a) We are asked to compute the Brinell hardness for the given indentation. for HB, where P= 1000 kg, d= 2.3 mm, and D= 10 mm.
Thus, the Brinell hardness is computed as

![=2*1000hg/\pi (10mm)[10mm-\sqrt{(1000^2-(2.3mm)^2} ]](https://tex.z-dn.net/?f=%3D2%2A1000hg%2F%5Cpi%20%2810mm%29%5B10mm-%5Csqrt%7B%281000%5E2-%282.3mm%29%5E2%7D%20%5D)
(b) This part of the problem calls for us to determine the indentation diameter d which will yield a 270 HB when P= 500 kg.
![d=\sqrt{D^2-[D-\frac{2P}{(HB)\pi D} } ]^2\\=\sqrt{(10mm)^2-[10mm-\frac{2*500}{450( \pi10mm)} } ]^2](https://tex.z-dn.net/?f=d%3D%5Csqrt%7BD%5E2-%5BD-%5Cfrac%7B2P%7D%7B%28HB%29%5Cpi%20D%7D%20%7D%20%5D%5E2%5C%5C%3D%5Csqrt%7B%2810mm%29%5E2-%5B10mm-%5Cfrac%7B2%2A500%7D%7B450%28%20%5Cpi10mm%29%7D%20%7D%20%5D%5E2)
Answer:
B) voltage at the sending end of the feeder = 2483.66 v
Explanation:
attached below is the the equivalent circuits and the remaining solution for option A
B) voltage = 2400 v
I =
= 20.83 A
calculate voltage at sending end ( Vs )
Vs = 2400 + 20.83 ∠ -cos^-1 (0.8) ( 0.75*2 + 0.5 + j 2 + j2 )
hence Vs = 2483.66 ∠ 0.961
therefore voltage at the sending end = 2483.66 v
Hopefully that helps you out and is this for history or science?
Answer:
C is the answer if not c then b
Answer: Compressed-air engine.
Explanation:
The submarine used a compressed-air engine, propelled by stored compressed air powering a reciprocating engine.
Hope this helps