Explanation:
thermal expansion ∝L = (δL/δT)÷L ----(1)
δL = L∝L + δT ----(2)
we have δL = 12.5x10⁻⁶
length l = 200mm
δT = 115°c - 15°c = 100°c
putting these values into equation 1, we have
δL = 200*12.5X10⁻⁶x100
= 0.25 MM
L₂ = L + δ L
= 200 + 0.25
L₂ = 200.25mm
12.5X10⁻⁶ *115-15 * 20
= 0.025
20 +0.025
D₂ = 20.025
as this rod undergoes free expansion at 115°c, the stress on this rod would be = 0
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, 
Creep rate at 800⁰C, 
.........................(1)
Creep rate at 700⁰C
.................(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
Given:
Temperature of water, 
= 
=273 +(-6) =267 K
Temperature surrounding refrigerator, 
= 
=273 + 21 =294 K
Specific heat given for water, 
= 4.19 KJ/kg/K
Specific heat given for ice, 
= 2.1 KJ/kg/K
Latent heat of fusion, 
= 335KJ/kg
Solution:
Coefficient of Performance (COP) for refrigerator is given by:
Max 
= 
= 
= 9.89
Coefficient of Performance (COP) for heat pump is given by:
Max 
= 
= 10.89
The lightning efficiency based on the scenario depicted will be C. 56 lumens/Watt, more efficient.
<h3>How to calculate the lightning efficiency</h3>
The efficiency of the incandescent bulb will be:
= 450/40 = 11.25 lumens per watt.
The efficiency of the LED bulb will be:
= 450/8 = 56 lumens per watt.
In this case, the LED bulb is more efficient than the incandescent bulb.
Therefore, the lighting efficiency will be 56 lumens/Watt, more efficient
Learn more lightning efficiency on:
brainly.com/question/25927632
