Answer:
Activation energy for creep in this temperature range is Q = 252.2 kJ/mol
Explanation:
To calculate the creep rate at a particular temperature
creep rate, ![\zeta_{\theta} = C \exp(\frac{-Q}{R \theta} )](https://tex.z-dn.net/?f=%5Czeta_%7B%5Ctheta%7D%20%3D%20C%20%5Cexp%28%5Cfrac%7B-Q%7D%7BR%20%5Ctheta%7D%20%29)
Creep rate at 800⁰C, ![\zeta_{800} = C \exp(\frac{-Q}{R (800+273)} )](https://tex.z-dn.net/?f=%5Czeta_%7B800%7D%20%3D%20C%20%5Cexp%28%5Cfrac%7B-Q%7D%7BR%20%28800%2B273%29%7D%20%29)
![\zeta_{800} = C \exp(\frac{-Q}{1073R} )\\\zeta_{800} = 1 \% per hour =0.01\\](https://tex.z-dn.net/?f=%5Czeta_%7B800%7D%20%3D%20C%20%5Cexp%28%5Cfrac%7B-Q%7D%7B1073R%7D%20%29%5C%5C%5Czeta_%7B800%7D%20%3D%201%20%5C%25%20per%20hour%20%3D0.01%5C%5C)
.........................(1)
Creep rate at 700⁰C
![\zeta_{700} = C \exp(\frac{-Q}{R (700+273)} )](https://tex.z-dn.net/?f=%5Czeta_%7B700%7D%20%3D%20C%20%5Cexp%28%5Cfrac%7B-Q%7D%7BR%20%28700%2B273%29%7D%20%29)
![\zeta_{800} = C \exp(\frac{-Q}{973R} )\\\zeta_{800} = 5.5 * 10^{-2} \% per hour =5.5 * 10^{-4}](https://tex.z-dn.net/?f=%5Czeta_%7B800%7D%20%3D%20C%20%5Cexp%28%5Cfrac%7B-Q%7D%7B973R%7D%20%29%5C%5C%5Czeta_%7B800%7D%20%3D%205.5%20%2A%2010%5E%7B-2%7D%20%20%5C%25%20per%20hour%20%3D5.5%20%2A%2010%5E%7B-4%7D)
.................(2)
Divide equation (1) by equation (2)
![\frac{0.01}{5.5 * 10^{-4} } = \exp[\frac{-Q}{1073R} -\frac{-Q}{973R} ]\\18.182= \exp[\frac{-Q}{1073R} +\frac{Q}{973R} ]\\R = 8.314\\18.182= \exp[\frac{-Q}{1073*8.314} +\frac{Q}{973*8.314} ]\\18.182= \exp[0.0000115 Q]\\](https://tex.z-dn.net/?f=%5Cfrac%7B0.01%7D%7B5.5%20%2A%2010%5E%7B-4%7D%20%7D%20%3D%20%5Cexp%5B%5Cfrac%7B-Q%7D%7B1073R%7D%20-%5Cfrac%7B-Q%7D%7B973R%7D%20%5D%5C%5C18.182%3D%20%5Cexp%5B%5Cfrac%7B-Q%7D%7B1073R%7D%20%2B%5Cfrac%7BQ%7D%7B973R%7D%20%5D%5C%5CR%20%3D%208.314%5C%5C18.182%3D%20%5Cexp%5B%5Cfrac%7B-Q%7D%7B1073%2A8.314%7D%20%2B%5Cfrac%7BQ%7D%7B973%2A8.314%7D%20%5D%5C%5C18.182%3D%20%5Cexp%5B0.0000115%20Q%5D%5C%5C)
Take the natural log of both sides
![ln 18.182= 0.0000115Q\\2.9004 = 0.0000115Q\\Q = 2.9004/0.0000115\\Q = 252211.49 J/mol\\Q = 252.2 kJ/mol](https://tex.z-dn.net/?f=ln%2018.182%3D%200.0000115Q%5C%5C2.9004%20%3D%200.0000115Q%5C%5CQ%20%3D%202.9004%2F0.0000115%5C%5CQ%20%3D%20252211.49%20J%2Fmol%5C%5CQ%20%3D%20252.2%20kJ%2Fmol)
I think it’s structural engineers but still check with the others
Answer:
A motion sensor uses one or multiple technologies to detect movement in an area. When a sensor detects motion, it sends a signal to your security systems control panel, which connects to your monitoring panel system. This alerts you and the monitoring center to a potential threat in your home.
Hope It Helps You................
Answer:
The coefficient of thermal expansion tells us how much a material can expand due to heat.
Explanation:
Thermal expansion occurs when a material is subjected to heat and changes it's shape, area and volume as a result of that heat. How much that material changes is dependent on it's coefficient of thermal expansion.
Different materials have different coefficients of thermal expansion (i.e. It is a material property and differs from one material to the next). It is important to understand how materials behave when heated, especially for engineering applications when a change in dimension might pose a problem or risk (eg. building large structures).