Answer:
C. both forces have the same magnitude
Explanation:
Here the action force is equal to the reaction force in accordance with the Newton's third law of motion.
Also when we apply the conservation of momentum so that the momentum bullet and the momentum of the gun are equal and according to the second law of motion by Newton, we have force equal to the rate of change in momentum.
We have the equation for momentum as:

Newton's second law is Mathematically given as:

Momentum is constant and the reaction time is equal, so the force exerted will also be equal.
Answer:
B = 0.157 T
Explanation:
Given that,
Length of the solenoid, l = 8 cm = 0.08 m
Number of turns in the wire, N = 2000
Current, I = 5 A
We need to find the strength of the magnetic field at the center of the solenoid. It is given by the formula as follows :
, N is number of turns per unit length of solenoid.
So,

So, the magnetic field at the center of the solenoid is 0.157 T.
Answer:
The question has some details missing, here is the complete question ; A -3.0 nC point charge is at the origin, and a second -5.0nC point charge is on the x-axis at x = 0.800 m. Find the net electric force that the two charges would exert on an electron placed at point on the x-axis at x = 0.200 m.
Explanation:
The application of coulonb's law is used to approach the question as shown in the attached file.