Final answer:
The net force on a falling object, which experiences an equal amount of force due to gravity and air resistance, is D) zero newtons. This is because the two forces cancel each other out, resulting in no acceleration for the object.
Step-by-step explanation:
In the given situation, a falling object with the force of gravity (10 newtons) is balanced by an equal but opposite force (the air resistance, also 10 newtons). According to Newton's second law, the net force on an object causes that object to accelerate.
Since the two forces exerted on the object are equal and act in opposite directions, they cancel each other out, resulting in no net force. Therefore, the acceleration of the object becomes zero. In such cases, the net force on the object is 0 newtons (option D).
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