1) Constant speed
2) Slowing down
3) Not moving
4) Speeding up
You'd get an extra 40/60 of the energy, or 2/3. Multiply 5/3 by the required energy to get the actual consumption.
1. 2500/60 joules/sec
2. 2,500Nm
On a roller coaster, the greatest potential energy is at the highest point of the roller coaster