Answer:
1.
2.
3.The results from part 1 and 2 agree when r = R.
Explanation:
The volume charge density is given as

We will investigate this question in two parts. First r < R, then r > R. We will show that at r = R, the solutions to both parts are equal to each other.
1. Since the cylinder is very long, Gauss’ Law can be applied.

The enclosed charge can be found by integrating the volume charge density over the inner cylinder enclosed by the imaginary Gaussian surface with radius ‘r’. The integration of E-field in the left-hand side of the Gauss’ Law is not needed, since E is constant at the chosen imaginary Gaussian surface, and the area integral is

where ‘h’ is the length of the imaginary Gaussian surface.

2. For r> R, the total charge of the enclosed cylinder is equal to the total charge of the cylinder. So,

3. At the boundary where r = R:

As can be seen from above, two E-field values are equal as predicted.
the answer is B! it would continue to expand.....just took the test XD
Answer:
The boat will be 74 .17 meters downstream by the time it reaches the shore.
Explanation:
Consider the vector diagrams for velocity and distance shown below.
converting 72 miles per hour to km/hr
we have 72 miles per hour 72 × 1.60934 = 115.83 km/hr
The velocity vectors form a right angled triangle, and can be solved using simple trigonometric laws


This is the vector angle with which the ship drifts away with respect to its northward direction.
<em>From the sketch of the displacement vectors, we can use trigonometric ratios to determine the distance the boat moves downstream.</em>
Let x be the distance the boat moves downstream.d



∴The boat will be 74 .17 meters downstream by the time it reaches the shore.
Answer:
"the force of attraction between two objects"
Explanation:
According to Newton's Universal Law of Gravitation, gravity is a force of attraction acting between objects that possess mass. The fact that we only observe gravitational attraction (as opposed to repulsion) makes gravity unique among the known forces.