Final answer:
The magnitude of the force with which one block acts on the other in the given system is 36 N. This is calculated using Newton's Second Law and Newton's Third Law of motion.
Step-by-step explanation:
The problem posed involves the concept of Newton's Third Law which states that for every action, there is an equal and opposite reaction. This means that the force exerted by one object on another is the same magnitude but in the opposite direction of the force that the second object exerts on the first.
In the given problem scenario, we have two objects with masses m = 2 kg and M = 3 kg, and an external force F = 90N being exerted on the system. But the forces acting within the system, specifically between the two blocks, would be due to the acceleration caused by the external force.
So, let's first calculate the total acceleration of the system. Using Newton's Second Law (F=ma), we get the system acceleration (a) by rearranging the elements to a = F/(m + M) => a = 90N / (2 kg + 3 kg) => a = 18 m/s^2.
The force with which one block acts on the other block would then be equal to this acceleration times the mass of the other block. Therefore, for the force by the 2 kg block on the 3 kg block, we have F = m * a => F = 2 kg * 18 m/s^2 = 36N. If we calculate the force by the 3 kg block on the 2 kg block, we reach the same result of 36N, indicating an equal and opposite force as per Newton's Third Law.
Therefore, the magnitude of the force with which one block acts on the other is 36 N, which makes the correct choice 4.
Learn more about Newton's Laws of Motion