Answer: Ok, first lest see out problem.
It says it's a Long cylindrical charge distribution, So you can ignore the border effects on the ends of the cylinder.
Also by the gauss law we know that E¨*2*pi*r*L = Q/ε0
where Q is the total charge inside our gaussian surface, that will be a cylinder of radius r and heaight L.
So Q= rho*volume= pi*r*r*L*rho
so replacing : E = (1/2)*r*rho/ε0
you may ask, ¿why dont use R on the solution?
since you are calculating the field inside the cylinder, and the charge density is uniform inside of it, you don't see the charge that is outside, and in your calculation actuali doesn't matter how much charge is outside your gaussian surface, so R does not have an effect on the calculation.
R would matter if in the problem they give you the total charge of the cylinder, so when you only have the charge of a smaller r radius cylinder, you will have a relation between r and R that describes how much charge density you are enclosing.
Answer:
The volume of a cylindrical conduit, 
where 
is the inner radius, 
is the outer radius, h is the length.
First of all, we would covert each parameter into centimeters.
length of the conduit, 
outer radius, 
inner radius, 
Insert the values in the volume formula,
Hence, the volume of metal in the conduit is 510. 12 cubic centimeters.
Answer:
You have to calculate
Explanation:
Work is done when a force that is applied to an object moves that object. The work is calculated by multiplying the force by the amount of movement of an object (W = F * d). A force of 10 newtons, that moves an object 3 meters, does 30 n-m of work.
B. How much work can be done in a given time. That’s why it’s measured occasionally I. “Horsepower.” It’s your ability to work fast and far.
Angle of incidence is 36° and so is the reflection. Both angles are equal.
