Answer:
a
Solid Wire
Stranded Wire 
b
Solid Wire
Stranded Wire
Explanation:
Considering the first question
From the question we are told that
The radius of the first wire is 
The radius of each strand is 
The current density in both wires is 
Considering the first wire
The cross-sectional area of the first wire is

= >
= >
Generally the current in the first wire is

=> 
=>
Considering the second wire wire
The cross-sectional area of the second wire is

=> 
=> 
Generally the current is

=> 
=> 
Considering question two
From the question we are told that
Resistivity is 
The length of each wire is 
Generally the resistance of the first wire is mathematically represented as
=>
=>
Generally the resistance of the first wire is mathematically represented as
=>
=>
The least number of component of a vector quantity is two. These are the x-component and the y-component.
The resultant vector, or vector as we refer to it in this item, can be calculated through the equation,
RV = sqrt ((Vx)² + (Vy)²)
From the equation, it can be noted that if we let Vx equal to zero,
RV = Vy
Similarly, if we let Vy be equal to zero then,
RV = Vx
Thus, it is still possible for the vector to become nonzero even if one of its components is zero.
The possible magnitude for the force of static friction on the stationary cart is 72.1 N.
The given parameters:
- <em>Applied force on the cart, F = 72.1 N</em>
<em />
Based on Newton's second law of motion, the force applied to object is directly proportional to the product of mass and acceleration of the object.
F = ma
Static frictional force is the force resisting the motion of an object at rest.

where;
is the frictional force

Thus, the possible magnitude for the force of static friction on the stationary cart is 72.1 N.
Learn more about Newton's second law of motion: brainly.com/question/25307325
It took so long because at the time there was no way for people to study the behavior formally. im not sure what helped it get recognized but i know wihelm wundt helped get it recongnized.
sorry i couldnt be much help