Answer:
y = 10.2 m
Explanation:
It is given that,
Charge, 
It is placed at a distance of 9 cm at x axis
Charge, 
It is placed at a distance of 16 cm at x axis
We need to find the point on the y-axis where the electric potential zero. The net potential on y-axis is equal to 0. So,

Here,

So,

Squaring both sides,

So, at a distance of 10.2 m on the y axis the electric potential equals 0.
Answer:
C. 0.2 Hertz
Explanation:
The frequency of a spring is equal to the reciprocal of the period:

where
f is the frequency
T is the period
For the spring in this problem,
T = 5 s
therefore, the frequency is

A. because as the merry-go-round spins the child accelerates towards the center of the merry-go-round at a uniform rate.