In order to solve this problem it is necessary to apply the concepts related to intensity and specifically described in Malus's law.
Malus's law warns that

Where,
Angle between the analyzer axis and the polarization axis
Intensity of the light before passing through the polarizer
The intensity of the beam from the first polarizer is equal to the half of the initial intensity

Replacing with our the numerical values we get


Therefore the intensity of the light that emerges from the filter is 
Answer:
The net force on the box is 2 N to the left.
The box will move to the left.
The acceleration on the box is 0.5 m/s^2 to the left.
Explanation:
Let's say movement to the right is positive and left is negative.
Bob: +10 N
John: -12 N
Add those together and you get a net force of -2 N, and the negative sign means that the box is moving to the left.
For the acceleration:
Fnet = ma
-2 = (4 kg)a
a = -0.5 m/s^2
Again, the negative sign in this answer means the box is being accelerated to the left.
Answer: when fish is stunning it's prey it's cause electric shock to the prey that's make it die and be able to be utilized by electric eel(fish generate electric surround)