Answer:
<em>The rise in temperature will be less than 5 °C in the second minute.</em>
Explanation:
According to heat conduction law, the rate of heating is proportional to the temperature difference or temperature gradient. The temperature gradient is what drives heat to move from a hotter body at a higher temperature gradient to a colder body at a lower temperature gradient. For the potato, the initial first minute raises the temperature to 5 °C, consequently reducing the temperature gradient between the potato and the heating element in the oven. <em>This reduced temperature gradient means that the rate at which it will conduct heat in the second minute will be lesser than that at the first minute</em>. This will continue till the potato and the heating element are at the same temperature, at which no temperature gradient will exist between them; stopping heat transfer between them.
Technician A is incorrect so that means Technician B is correct.
Answer: 100% (double)
Explanation:
The question tells us two important things:
- Mass remains constant
- Volume remains constant
(We can think in a gas enclosed in a closed bottle, which is heated, for instance)
In this case we know that, as always the gas can be considered as ideal, we can apply the general equation for ideal gases, as follows:
- State 1 (P1, V1, n1, T1) ⇒ P1*V1 = n1*R*T1
- State 2 (P2, V2, n2, T2) ⇒ P2*V2 = n2*R*T2
But we know that V1=V2 and that n1=n2, som dividing both sides, we get:
P1/P2 = T1/T2, i.e, if T2=2 T1, in order to keep both sides equal, we need that P2= 2 P1.
This result is just reasonable, because as temperature measures the kinetic energy of the gas molecules, if temperature increases, the kinetic energy will also increase, and consequently, the frequency of collisions of the molecules (which is the pressure) will also increase in the same proportion.
Answer:
B only
Explanation:
Squeeze-type resistance spot welding (STRSW)is a type of electric resistance welding that brings about the weld on interfacing sheet metal pieces through which heat generated from electric resistance bring about fusion and welding of the two pieces together
Therefore, it is not meant for opening but joints but it can be used for making replacement spot welds adjacent to the original spot weld due to the smaller heat affected zone (HAZ) created by the STRSW process.
