Why Does a Spoon Become Warmer When Stirring Hot Chocolate?
What happens when a student stirs a cup of hot chocolate with a cold metal spoon and observes that the spoon becomes warmer?
According to the law of conservation of energy, which answer choice best describes why the spoon became warmer?
a) The high-energy hot chocolate particles transfer some of their energy to the spoon particles, which causes the spoon to become warmer.
b) The high-energy spoon particles destroy some of the hot chocolate particles, which causes the spoon to become warmer.
c) The high-energy hot chocolate particles destroy some of the spoon particles, which causes the spoon to become warmer.
d) The high-energy spoon particles transfer some of their energy to the hot chocolate particles, which causes the spoon to become warmer.
Explanation:
When a student stirs a cup of hot chocolate with a cold metal spoon and observes that the spoon becomes warmer, it is due to the transfer of energy according to the law of conservation of energy. The correct answer is: a) The high-energy hot chocolate particles transfer some of their energy to the spoon particles, which causes the spoon to become warmer.
The Law of Conservation of Energy states that energy cannot be created or destroyed, only transferred or converted from one form to another. When the hot chocolate particles collide with the cold metal spoon, some of the kinetic energy from the hot chocolate particles is transferred to the spoon particles. This transfer of energy causes the spoon to become warmer as the particles in the spoon gain kinetic energy.
As a result of this transfer of energy, the spoon's particles move faster and have higher kinetic energy, leading to an increase in the temperature of the spoon. This phenomenon is an example of thermal conduction, where heat is transferred from the higher-temperature substance (hot chocolate) to the lower-temperature substance (spoon) through direct contact.
In conclusion, when a student stirs a cup of hot chocolate with a cold metal spoon and observes that the spoon becomes warmer, it is because the high-energy hot chocolate particles transfer some of their energy to the spoon particles, causing the spoon to heat up.