Answer:
a) 
b)
Explanation:
Given that:
diameter d = 12 in
thickness t = 0.25 in
the radius = d/2 = 12 / 2 = 6 in
r/t = 6/0.25 = 24
24 > 10
Using the thin wall cylinder formula;
The valve A is opened and the flowing water has a pressure P of 200 psi.
So;
b)The valve A is closed and the water pressure P is 250 psi.
where P = 250 psi
The free flow body diagram showing the state of stress on a volume element located on the wall at point B is attached in the diagram below
Answer:
a) 
, b) Yes.
Explanation:
a) The maximum thermal efficiency is given by the Carnot's Cycle, whose formula is:
b) The claim of the inventor is possible since real efficiency is lower than maximum thermal efficiency.
Answer: the increase in the external resistor will affect and decrease the current in the circuit.
Explanation: A battery has it own internal resistance, r, and given an external resistor of resistance, R, the equation of typical of Ohm's law giving the flow of current is
E = IR + Ir = I(R + r)........(1)
Where IR is the potential difference flowing in the external circuit and Or is the lost voltage due to internal resistance of battery. From (1)
I = E/(R + r)
As R increases, and E, r remain constant, the value (R + r) increases, hence the value of current, I, in the external circuit decreases.
