1. The problem statement, all variables and given/known data If it can be assumed that the car has the same speed at points A and E, which of the following statements is true? a. The net work done in this system is 0 b. The net work done in this system is positive c. The net work done in this system is negative d. The net work done in this system is positive for the roller coaster but 0 for the slope e. The net work done in this system is 0 for the roller coaster but positive for the slope 2. Relevant equations We know that in this scenario, energy is completely cosnerved. Therefore, the total energy at A equals the total energy at E. 3. The attempt at a solution It can't be (d.) or (e.) because the work is the same for the roller coaster and slope due to Newton's Third Law. I think it's (a.) since the net change in energy is 0, since the cart returns to position E with the same potential energy. Correct answer is (b.), I don't see why.