Answer:
7.894 MJ
Explanation:
Given that:
The mass of the saturated water vapor = 3.7 kg
The pressure of the saturated water vapor = 0.4 MPa
From saturated properties of steam tables when the pressure is at 0.4 Mpa
The enthalpy in (kJ/kg);
hf = 604.7 kJ/kg
hg = 2738.1 kJ/kg
The rejected heat during this process is:
Q = m(hg - hf)
Q = 3.7(2738.1 - 604.7) kJ/kg
Q = 3.7(2133.4) kJ/kg
Q = 7893.58 kJ/kg
Q = 7.894 MJ
Answer:
The driving force for (a) heat transfer is temperature difference. (b) electric current is voltage difference. (c) fluid flow is pressure or hydraulic head difference.
Explanation: (a) The driving force for heat transfer is temperature difference. Heat transfer between two mediums is possible only if the two mediums are at different temperature, the higher the temperature, the higher the heat transfer.
(b) The driving force for electric current is voltage difference. Voltage difference is defined as the potential difference in charge between two points in electrical field. For electric current to occur,the voltage must be high.
(c) The driving force for fluid flow is pressure difference or hydraulic head difference. For fluid to move upward,it requires energy.
Answer:
It is very important because scientists, especially the ones with empirical experiments and results, are prone to error and the empirical data is in need to be under strict observation done not only by many scientists but also by expermiented ones. This guards everybody to change the parameters suddenly which can affect the real results of an experiment
Explanation:
For a parallel circuit with two resistors, the total resistance is calculated from the expression:
1/R = 1/R1 + 1/R2
We are given the total resistance, R, which is 20 ohms and R2 which is 75 ohms. We calculate R1 as follows:
1/20 = 1/R1 + 1/75
1/R1 = 11/300
R1 = 27.27 ohms
