Heat always flows from higher temperature to lower temperature. So option A. heat will flow from the air into the coolant is the correct answer.
It's because lightbulbs need to carry an electric current within a range of resistance so that the material doesn't without breaking down.
<span>The correct answer is D) fusion. In fact, nuclear fusion occurs when two (or more) small nuclei combine to form a heavier nucleus. In the process, a large amount of energy is released, according to Einstein's formula </span>

<span>, where m is the mass converted into energy in the reaction. An example of nuclear fusion is the fusion of two nuclei of hydrogen into a nucleus of helium-4.</span>