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:
h = 16.67m
Explanation:
If the kinetic energy of the cylinder is 510J:


Where the inertia is given by:

Replacing this value:

Speed of the block will therefore be:

By conservation of energy:
Eo = Ef
Eo = 0

So,

Solving for h we get:
h=16.67m
Answer:
The answer is 218
Explanation:
Weight = mass * gravitational acceleration
weight is represented by F
F = 25kg (8.7)
(I'm pretty sure that you don't have to include the meters per second/per second thing)