Answer:
The change in temperature per minute for the sample, dT/dt is 71.
°C/min
Step-by-step explanation:
The given parameters of the question are;
The specific heat capacity for glass, dQ/dT = 0.18 (kcal/°C)
The heat transfer rate for 1 kg of glass at 20.0 °C, dQ/dt = 12.9 kcal/min
Given that both dQ/dT and dQ/dt are known, we have;
![\dfrac{dQ}{dT} = 0.18 \, (kcal/ ^{\circ} C)](https://tex.z-dn.net/?f=%5Cdfrac%7BdQ%7D%7BdT%7D%20%3D%200.18%20%5C%2C%20%28kcal%2F%20%5E%7B%5Ccirc%7D%20C%29)
![\dfrac{dQ}{dt} = 12.9 \, (kcal/ min)](https://tex.z-dn.net/?f=%5Cdfrac%7BdQ%7D%7Bdt%7D%20%3D%2012.9%20%5C%2C%20%28kcal%2F%20min%29)
Therefore, we get;
![\dfrac{\dfrac{dQ}{dt} }{\dfrac{dQ}{dT} } = {\dfrac{dQ}{dt} } \times \dfrac{dT}{dQ} = \dfrac{dT}{dt}](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Cdfrac%7BdQ%7D%7Bdt%7D%20%7D%7B%5Cdfrac%7BdQ%7D%7BdT%7D%20%7D%20%3D%20%7B%5Cdfrac%7BdQ%7D%7Bdt%7D%20%7D%20%5Ctimes%20%5Cdfrac%7BdT%7D%7BdQ%7D%20%3D%20%5Cdfrac%7BdT%7D%7Bdt%7D)
![\dfrac{dT}{dt} = \dfrac{\dfrac{dQ}{dt} }{\dfrac{dQ}{dT} } = \dfrac{12.9 \, kcal / min }{0.18 \, kcal/ ^{\circ} C } = 71.\overline 6 \, ^{\circ } C/min](https://tex.z-dn.net/?f=%5Cdfrac%7BdT%7D%7Bdt%7D%20%3D%20%5Cdfrac%7B%5Cdfrac%7BdQ%7D%7Bdt%7D%20%7D%7B%5Cdfrac%7BdQ%7D%7BdT%7D%20%7D%20%3D%20%5Cdfrac%7B12.9%20%5C%2C%20kcal%20%2F%20min%20%7D%7B0.18%20%5C%2C%20kcal%2F%20%5E%7B%5Ccirc%7D%20C%20%7D%20%20%20%3D%2071.%5Coverline%206%20%5C%2C%20%5E%7B%5Ccirc%20%7D%20C%2Fmin)
For the sample, we have the change in temperature per minute, dT/dt, presented as follows;
![\dfrac{dT}{dt} = 71.\overline 6 \, ^{\circ } C/min](https://tex.z-dn.net/?f=%5Cdfrac%7BdT%7D%7Bdt%7D%20%20%3D%2071.%5Coverline%206%20%5C%2C%20%5E%7B%5Ccirc%20%7D%20C%2Fmin)