Answer
Sump heater
Explanation
Answer:
The 5/16 – 24 UNF is stronger because it has more tensile load capacity.
Tensile load capacity for M8 -1.25 = 5670 lb
Tensile load capacity for M8 -1 = 6067 lb
Explanation:
For 5/16 - 18 UNC thread:
D = 0.3125
n = 18
Therefore the tensile load capacity is = 100000 X (0.7854 X (0.3125 - 0.9743/ 18) ^2
= 5243 lb.
Similarly for 5/16 - 24 UNF , only the n value changes to 24
we get the tensile load capacity = 5806.6 lb
Hence the 5/16 – 24 UNF is stronger because it has more tensile load capacity.
For metric Bolts:
We have to consider all values in SI units
Strength = 689 MPa
We get for M8 -1.25:
Tensile load capacity as = 689 X 36.6 = 25223 N = 5670 lb
For M8 -1:
Tensile load capacity as = 689 X 39.167 = 26986 N = 6067lb
Answer:
a) 149 kJ/mol, b) 6.11*10^-11 m^2/s ,c) 2.76*10^-16 m^2/s
Explanation:
Diffusion is governed by Arrhenius equation

I will be using R in the equation instead of k_b as the problem asks for molar activation energy
I will be using

and
°C + 273 = K
here, adjust your precision as neccessary
Since we got 2 difusion coefficients at 2 temperatures alredy, we can simply turn these into 2 linear equations to solve for a) and b) simply by taking logarithm
So:

and

You might notice that these equations have the form of

You can solve this equation system easily using calculator, and you will eventually get

After you got those 2 parameters, the rest is easy, you can just plug them all including the given temperature of 1180°C into the Arrhenius equation

And you should get D = 2.76*10^-16 m^/s as an answer for c)