Final answer:
The magnitude of the other force acting on the 5.0-kg object, given that it accelerates at 2.0 m/s² in the positive y-direction, is 10.0 N.
Step-by-step explanation:
To find the magnitude of the other force acting on the 5.0-kg object, we can use Newton's second law of motion, which states that the net force acting on an object is equal to the mass of the object times its acceleration (F = ma). In this case, we are given that the object accelerates at 2.0 m/s² in the positive y-direction, and we know the object's mass is 5.0 kg. Therefore, the net force in the y-direction can be calculated as (5.0 kg)(2.0 m/s²) = 10.0 N. The force in the positive x-direction (12.0 N) is perpendicular to the acceleration and does not affect the net force in the y-direction. Therefore, the other force acting on the object must be 10.0 N in the positive y-direction, as it is the only other force contributing to the net force in that direction.