Question

which describes how fast - moving particles assist in transferring thermal energy to a cup after hot tea is poured into it?
they replace slow - moving particles.
they collide with slow - moving particles.
they collide with other fast - moving particles.
they are replaced by slow - moving particles.

Explanation:

When hot tea (with fast - moving particles) is poured into a cup, thermal energy transfer occurs through particle collisions. According to the kinetic theory of matter, fast - moving particles (in the hot tea) collide with the slower - moving particles (in the cup material). In a collision, kinetic energy is transferred from the more energetic (fast - moving) particles to the less energetic (slow - moving) particles.

• Option 1: Particles do not "replace" each other in the sense of thermal energy transfer. Thermal energy transfer is about energy exchange through collisions, not particle substitution.
• Option 3: Colliding with other fast - moving particles (within the hot tea itself) does not directly assist in transferring thermal energy to the cup. The transfer to the cup is from tea particles to cup particles.
• Option 4: The concept of being "replaced" is not relevant to the mechanism of thermal energy transfer. Thermal energy transfer is a result of energy exchange during collisions, not particle replacement.

Answer:

They collide with slow - moving particles.