Answer:
first set
1. 784.56J
2. 1600J
3. 784.8J
4. Kinetic
second set
1. 400J
2. 392.4J
3. 792.4J
4. Potential
third
1. 56J
2. 784J
3. 840J
4. Potential
fourth
1. the potential changes as the energy depletes and kinetic energy do stay the same because they're falling from the same point
2. the potential energy falls down to the total energy because during the process all the excess energy decreases
3. yes, the total amount of energy is how much energy it holds throughout the process.