To determine the answer of Part A draw the equilateral triangle and the to determine the coordinates of of the third charge use that triangle.
To calculate the gravitational field strength in part B from each of the charges use the following equation.
E=kcq/r2
If you would add those values then you can use the symmetry about the y axis to make the vector addition a litter easier.<span />
Answer:

Step-by-step explanation:
We want to find the equation of a circle with a center at (7, 2) and a point on the circle at (2, 5).
First, recall that the equation of a circle is given by:

Where (<em>h, k</em>) is the center and <em>r</em> is the radius.
Since our center is at (7, 2), <em>h</em> = 7 and <em>k</em> = 2. Substitute:

Next, the since a point on the circle is (2, 5), <em>y</em> = 5 when <em>x</em> = 2. Substitute:

Solve for <em>r: </em>
<em />
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Simplify. Thus:

Finally, add:

We don't need to take the square root of both sides, as we will have the square it again anyways.
Therefore, our equation is:

Answer:
Question 11.1
At 7 : 00 pm in Sydney, it will be 10 : 00 pm in Berlin.
Question 11.2
Place | Time
Sydney | 5 : 00 pm
Berlin | 8 : 00 pm
It would be a good time for Mark and Hans to cha,t when it's 5 : 00 pm in Sydney and 8 : 00 pm in Berlin.
hope that helps ...
Step-by-step explanation:
yes the are similar because of AA Theorem
EAB is similar to ECD