Answer:
475 J
Step-by-step explanation:
At the top of the feature, Robert has 475 J of kinetic energy and 2240 J of gravitational potential energy. According to the law of conservation of energy, the total energy of a system is constant, so the sum of the kinetic energy and gravitational potential energy at the top of the feature is equal to the sum of the kinetic energy and gravitational potential energy at the bottom of the feature.
Since Robert is at the bottom of the feature, he has lost all of his gravitational potential energy. Therefore, the total energy he has at the bottom of the feature is equal to his kinetic energy at the top of the feature:
Total energy = Kinetic energy at top = 475 J
Therefore, the answer is 475 J, which is option D.