3. In the four cases shown below, a cart (with mass shown) very slowly approaches a ramp. The units of fue equal the grids shown are meters; use the grid to judge the height and slope of each ramp. 20 kg 50 kg Case A Case B 60 kg 30 kg Case C Case D (a) Rank the cases based on the final speed of each cart upon reaching the bottom of the incline. Greatest Speed Least Speed Explain how this ranking could be determined without making any calculations. Write an equation stating conservation of energy as part of your explanation. (b) Rank the cases based on the kinetic energy of each cart upon reaching the bottom of the incline. Greatest KE Least KE