Final answer:
The magnitude of the net force on the 2.40kg fan-cart generating a 0.360N thrust, with no frictions or drag, is simply the thrust force itself, which is 0.360N.
Step-by-step explanation:
The student asked about the magnitude of the net force on a 2.40kg fan-cart that is moving to the right and generating a 0.360N thrust. As friction and drag are neglected, the only force acting on the fan-cart in the horizontal direction is this thrust.
Therefore, the net external force on the fan-cart is simply the force of the thrust, which is 0.360N. This is because there are no opposing forces mentioned in the problem. Hence, option B is correct.