Answer:
The axial force is 
Explanation:
From the question we are told that
The diameter of the shaft steel is 
The length of the cylindrical bushing 
The outer diameter of the cylindrical bushing is 
The diametral interference is 
The coefficient of friction is 
The Young modulus of steel is 
The diametral interference is mathematically represented as

Where
is the pressure (stress) on the two object held together
So making
the subject

Substituting values


Now he axial force required is

Where A is the area which is mathematically evaluated as

So 
Substituting values


The centripetal acceleration of an object is given by the relation,

where Ac = centripetal acceleration =
R = radius of rotation = 15 m
V = speed of astronaut
Hence, 
solving this we get, V = 38.34 m/s
The chromosome pair that attaches to fiber stretching is called Centrioles
Answer:
Option A
The cost of keeping the semiconductor below the critical temperature is unreasonable
Explanation:
First of all, we need to understand what superconductors are. Superconductors are special materials that conduct electrical current with almost zero resistance. This means that there is little or no need for a voltage source to be connected to them. As a matter of fact, once a superconductor is connected to a power supply, one can remove the power supply and the current will still flow.
However, most superconducts can only conduct at very low temperatures up to -200 degrees Celcius. This is because, at that temperature, their atoms and molecules are relatively settled, hence they pose little or no resistance to the flow of current.
This as you can guess is extremely difficult to do, as you will need a lot of effort to cool it to that temperature and maintain it.
This makes option a the answer:
The cost of keeping the semiconductor below the critical temperature is unreasonable.