Answer:
b). The same for all pipes independent of the diameter
Explanation:
We know,


From the above formulas we can conclude that the thermal resistance of a substance mainly depends upon heat transfer coefficient,whereas radius has negligible effects on heat transfer coefficient.
We also know,
Factors on which thermal resistance of insulation depends are :
1. Thickness of the insulation
2. Thermal conductivity of the insulating material.
Therefore from above observation we can conclude that the thermal resistance of the insulation is same for all pipes independent of diameter.
Answer:
net amount of energy change of the air in the room during a 30-min period = 660KJ
Explanation:
The detailed calculation is as shown in the attached file.
Answer:
a.) -147V
b.) -120V
c.) 51V
Explanation:
a.) Equation for potential difference is the integral of the electrical field from a to b for the voltage V_ba = V(b)-V(a).
b.) The problem becomes easier to solve if you draw out the circuit. Since potential at Q is 0, then Q is at ground. So voltage across V_MQ is the same as potential at V_M.
c.) Same process as part b. Draw out the circuit and you'll see that the potential a point V_N is the same as the voltage across V_NP added with the 2V from the other box.
Honestly, these things take practice to get used to. It's really hard to explain this.