Answer:
a. The magnitude of the tension in the string is greater than the magnitude of the weight of the rock.
Explanation:
During the motion of the rock while it is in downward motion we can say

since it is performing circular motion so we will have its acceleration towards its center



So at the lowest point of the path we can say

so correct answer is
a. The magnitude of the tension in the string is greater than the magnitude of the weight of the rock.
the answer is a because they start on the north side
Answer:
The direction of the magnetic field at point Z; Into the screen
Explanation:
This seems like an incomplete question..