Answer:

Explanation:
If we assume that the Earth is a spherical conductor, according to Gauss's Law, the electric field is given by:

Here k is the Coulomb constant, the excess charge on the Earth's surface and r its radius. Solving for q:

Answer:
P = 14700 J
Explanation:
Given that,
Mass of a piano, m = 75 kg
It is delivered throughout the window of a 6th story apartment which is 20 m above the ground.
We need to find the potential energy of the piano. It is given by :
P = mgh
Putting all the values,
P = 75 kg × 9.8 m/s² × 20 m
P = 14700 J
So, the potential energy of the piano is 14700 J.
There must be movement in the same direction as the force put on the object. Hope this helps!
The answer to this question is b