Final answer:
The given question asks for the potential energy gained by a train ascending a gradient but lacks the necessary mass of the train to calculate the potential energy. The gradient likely refers to a 5.5% grade. Without the train's mass, we cannot accurately answer the question or select from the provided options.
Step-by-step explanation:
The question is asking how much potential energy is gained by a train that must climb a constant gradient of 5.5 and ascends 100 meters. Gradient in this context means the percent grade, which is the vertical height change for each 100 horizontal units, meaning that for every 100 meters travelled horizontally, the train climbs 5.5 meters vertically. To find the potential energy gained, we would use the formula for gravitational potential energy: PE = mgh, where m is the mass of the object, g is the acceleration due to gravity (9.8 m/s2), and h is the height.
However, in the context of this question, there seems to be a misunderstanding or lack of necessary information, as none of the given options (A. 550 J, B. 500 J, C. 450 J, D. 400 J) can be verified without the mass of the train. Additionally, the gradient value given (5.5) would likely correspond to a 5.5% grade, which is a common way of expressing slope in the context of railway gradients. To calculate potential energy, we would need to know the mass of the train and the actual vertical height the train ascends (which would be 5.5 m for a 100 m horizontal distance if a gradient of 5.5% is indeed being referred to).