The second option rolling friction
Answer:
B) they show which way iron shavings would align themselves
Explanation:
Let's analyze each statement:
A) they are not affected by their own source --> this is true for both magnetic and electric fields. In fact, both fields are produced (and so affected) by a source (a magnet or a current in the magnetic field case, and an electric charge in the electric field case)
B) they show which way iron shavings would align themselves --> this is only true for the magnetic field. In fact, the pieces of iron will align according to the magnetic field; however, since they are electrically neutral, they are not affected at all by an electric field.
C) they re stronger near the source and get weaker farther away --> true for both magnetic and electric fields.
D) the closer the fields lines, the stronger the fields --> also true for both magnetic and electric fields.
So, the correct answer is B.
The graph is one single line and, as a system solution refers to an intersection point (in other words, a point in common), we affirm both equations share all of their points and thus, such system has infinite solutions.
Answer:
Net force = 250 N
Explanation:
Given that,
The mass of a teacher, m = 75 kg
As the parachute opens, the system experiences a 1000N drag.
We need to find the magnitude of net force acting on the teacher. 2 forces are acting on her i.e. drag force and weight.
Net force,
F = mg-D
= 75(10)-1000
= -250 N
Hence, the net force is 250 N and it is acting in the upward direction.