Answer:
The energy possessed by a river when it is on top of a hill or a water fall is the potential energy . That is , as long as water is at some height above the ground level, it will have potential energy due to the influence of gravity . But once it starts flowing, the motion or movement is responsible for the kinetic energy.
Step-by-step explanation:
Energy due to the position or state of an object is gravitational potential energy. Once the object starts moving, it has a certain velocity. Velocity possessed by a mass ( or an object ) will give rise to kinetic energy.
For a given object, It is conservation of energy which basically explains this. The total energy should always remain constant during a process.
For the river waters, the potential energy due to its state is converted to kinetic energy of its motion.