All that business about the crane and the rope and the falling
is only there to confuse us.
The piano ended up 5 meters above the ground.
Potential energy = (mass) (gravity) (height)
= (200 kg) (9.81 m/s²) (5 m)
= (200 · 9.81 · 5) (kg-m²/s²)
= 9,810 joules .
Answer:

Explanation:
As given point p is equidistant from both the charges
It must be in the middle of both the charges
Assuming all 3 points lie on the same line
Electric Field due a charge q at a point ,distance r away

Where
- q is the charge
- r is the distance
-
is the permittivity of medium
Let electric field due to charge q be F1 and -q be F2
I is the distance of P from q and also from charge -q
⇒
F1
F2
⇒
F1+F2=
I believe the answer should be D