Complete Question
The complete question is shown on the first uploaded image
Answer:
The magnetic field is 
And the direction is 
Explanation:
From the question we are told that
The magnetic field at the center is 
Generally magnetic field is mathematically represented as

We are told that it is equal to 1mT
So

From the first diagram we see that the effect of the current flowing in the circular loop is (i.e the magnetic field generated)

This implies that the effect of a current flowing in the smaller semi-circular loop is (i.e the magnetic field generated)

and for the larger semi-circular loop is

Now a closer look at the second diagram will show us that the current in the semi-circular loop are moving in the opposite direction
So the net magnetic field would be





Recall 
So

Using the Right-hand rule we see that the direction is into the page which is 
Around 8 hours and 20 minutes
Explanation:
I divided 500 by 60 and got 8.3333333333 and i round it up to 8.20, so it is 8 hours and 20 minutes.
Answer:
a. The station is rotating at 
b. the rotation needed is 
Explanation:
We know that the centripetal acceleration is

where
is the rotational speed and r is the radius. As the centripetal acceleration is feel like an centrifugal acceleration in the rotating frame of reference (be careful, as the rotating frame of reference is <u>NOT INERTIAL,</u> the centrifugal force is a fictitious force, the real force is the centripetal).
<h3>a. </h3>
The rotational speed is :




Knowing that there are
in a revolution and 60 seconds in a minute.


<h3>b. </h3>
The rotational speed needed is :




Knowing that there are
in a revolution and 60 seconds in a minute.


Answer:
E1 = 2996.667N/C E2 = 11237.5N/C
Explanation:
E1 = kQ1/r^2
=8.99 x 10^9 x 30 x 10^-9/(30x10^-2)^2
= 2996.667N/C
E2 = kQ2/r^2
= 8.99 x 10^9 x 50 x 10^-9/(20x10^-2)^2
= 11237.5N/C
The direction are towards the point a