If some rice is poured in boiling water will the rice be cooked without any further supplying of heat?

No, the rice will not be fully cooked without supplying additional heat. While pouring rice into boiling water initiates the cooking process, the heat from the boiling water alone may not be sufficient to cook the rice thoroughly. The rice needs to absorb water and continue cooking for a certain amount of time, typically requiring sustained heat to reach the desired texture and doneness.