<h2>The flux through each face is q/6ε₀ .</h2>
Explanation:
The charge q is placed at the center of the cube of side L
According to Gauss's law the flux through any closed surface is q/ε₀
here q is the charge enclosed .
In this case cube has the six faces . The flux through each face = q/6ε₀
In the second case The cube has the face with length L₁
The flux through each face = q/6ε₀
Thus flux through the cube does not depend upon the size of the cube .
The rod transferred negatively charged particle to the metal sphere. The rod becomes less negatively charged than it was originally (originally it was charged to -21 nc, now it has -8, and -8>-21), so it must have moved 13 nc of negative charge to the sphere.
The frequency of the wheel is given by:

where N is the number of revolutions and t is the time taken. By using N=100 and t=10 s, we find the frequency of the wheel:

And now we can find the angular speed of the wheel, which is related to the frequency by:
Of a rope wrapped around a pulley chain
Answer is: 1973.17N aprox.
step by step in the pic below