Answer:
![T_b=107.3784\ ^{\circ}C](https://tex.z-dn.net/?f=T_b%3D107.3784%5C%20%5E%7B%5Ccirc%7DC)
Explanation:
Given:
- thickness of the base of the kettle,
![dx=0.52\ cm=5.2\times 10^{-3}\ m](https://tex.z-dn.net/?f=dx%3D0.52%5C%20cm%3D5.2%5Ctimes%2010%5E%7B-3%7D%5C%20m)
- radius of the base of the kettle,
![r=0.12\ m](https://tex.z-dn.net/?f=r%3D0.12%5C%20m)
- temperature of the top surface of the kettle base,
![T_t=100^{\circ}C](https://tex.z-dn.net/?f=T_t%3D100%5E%7B%5Ccirc%7DC)
- rate of heat transfer through the kettle to boil water,
![\dot Q=0.409\ kg.min^{-1}](https://tex.z-dn.net/?f=%5Cdot%20Q%3D0.409%5C%20kg.min%5E%7B-1%7D)
- We have the latent heat vaporization of water,
![L=2260\times 10^3\ J.kg^{-1}](https://tex.z-dn.net/?f=L%3D2260%5Ctimes%2010%5E3%5C%20J.kg%5E%7B-1%7D)
- and thermal conductivity of aluminium,
![k=240\ W.m^{-1}.K^{-1}](https://tex.z-dn.net/?f=k%3D240%5C%20W.m%5E%7B-1%7D.K%5E%7B-1%7D)
<u>So, the heat rate:</u>
![\dot Q=\frac{0.409\times 2260000}{60}](https://tex.z-dn.net/?f=%5Cdot%20Q%3D%5Cfrac%7B0.409%5Ctimes%202260000%7D%7B60%7D)
![\dot Q=15405.67\ W](https://tex.z-dn.net/?f=%5Cdot%20Q%3D15405.67%5C%20W)
<u>From the Fourier's law of conduction we have:</u>
![\dot Q=k.A.\frac{dT}{dx}](https://tex.z-dn.net/?f=%5Cdot%20Q%3Dk.A.%5Cfrac%7BdT%7D%7Bdx%7D)
![\dot Q=k\times \pi.r^2\times \frac{T_b-T_t}{5.2\times 10^{-3}}](https://tex.z-dn.net/?f=%5Cdot%20Q%3Dk%5Ctimes%20%5Cpi.r%5E2%5Ctimes%20%5Cfrac%7BT_b-T_t%7D%7B5.2%5Ctimes%2010%5E%7B-3%7D%7D)
where:
area of the surface through which conduction occurs
temperature of the bottom surface
![15405.67=240\times \pi\times 0.12^2\times \frac{T_b-100}{5.2\times 10^{-3}}](https://tex.z-dn.net/?f=15405.67%3D240%5Ctimes%20%5Cpi%5Ctimes%200.12%5E2%5Ctimes%20%5Cfrac%7BT_b-100%7D%7B5.2%5Ctimes%2010%5E%7B-3%7D%7D)
is the temperature of the bottom of the base surface of the kettle.
Answer:
Showing results for Two point charge q, separated by 1.5cm have change value of +2.0 and -4.0AND/C respectively what is the magnitude of the Electric force midway between them?
Search instead for Two point charge q, seperated by 1.5cm have change value of +2.0 and -4.0N/C respectively what is the magnitude of the Electric force midway between them?
When you heat a certain substance with a difference of temperature
![\Delta T](https://tex.z-dn.net/?f=%5CDelta%20T)
the heat (energy) you must give to it is
![E(=Q) =mc\Delta T](https://tex.z-dn.net/?f=E%28%3DQ%29%20%3Dmc%5CDelta%20T)
where
![c](https://tex.z-dn.net/?f=c)
is the specific heat of that substance (given in J/(g*Celsius))
In this case
![E=645*0.3850*(28.22-13.20) =3729.8 (Joule)](https://tex.z-dn.net/?f=E%3D645%2A0.3850%2A%2828.22-13.20%29%20%3D3729.8%20%28Joule%29)
Observation: the specific heat of a substance is given in J/(g*Celsius) or J/(g*Kelvin) because on the temperature scale a
difference of 1 degree Celsius = 1 degree Kelvin
Answer:
B is the best answer for the question