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)
Answer: 78.89%
Explanation:
Given : Sample size : n= 1200
Sample mean : 
Standard deviation : 
We assume that it follows Gaussian distribution (Normal distribution).
Let x be a random variable that represents the shaft diameter.
Using formula, 
, the z-value corresponds to 2.39 will be :-
z-value corresponds to 2.60 will be :-
Using the standard normal table for z, we have
P-value = 
Hence, the percentage of the diameter of the total shipment of shafts will fall between 2.39 inch and 2.60 inch = 78.89%
Answer:
Explanation:
Enforcing OSHA, Occupational Safety and Health Administration, standards is not a job for electricians, lawmakers or tax collectors. The right answer is safety inspectors.
Answer:
Carpenter — A carpenter is someone who works with wood. They build houses and make cabinets etc.
Logging — Loggers are people who cut trees. They use strong chain saws to cut trees.
Shipwrights — Shipwrights build, design, and repair all sizes of boats.
Wood Machinist — Wood Machinists repair and cut timber or any kind of wood for construction projects. They also operate woodworking machines, as their name suggest.
Furniture finishers — Furniture finishers shape, decorate, and restore damaged and worn out furniture.
Answer:
The general rule of thumb is that the SMALLER a substance's atoms and the STRONGER the bonds, the harder the substance. Two of the strongest forms of chemical bonds are the ionic and covalent bonds.
Explanation:
