Question

1. a boy and his younger sister are at the zoo on a hot day. they each buy a cold lemonade. the boy buys a large lemonade and his sister buys a small. they set their cups on a hot table and wait a while before they start drinking. when they finally begin to drink their lemonade, the girl complains that her drink is no longer cold. however, the brother states that his larger drink is still cold.

what conclusions could the boy and girl accurately draw from their observations? choose the two that apply.

• a. energy from the hot table and warm air is transferred to the cold cups of lemonade.
• b. the particles in the warmer cup of lemonade have more kinetic energy than the particles in the colder cup of lemonade.
• c. the thermal energy of a liquid is the same regardless of its size.
• d. if there are two different amounts of the same liquid, the temperature is a good way to compare their thermal energies.

Explanation:

• Option A: Heat transfer occurs from the hot table and warm air (higher - temperature objects) to the cold lemonade (lower - temperature object) by conduction (from the table) and convection/radiation (from the air). This is in line with the second law of thermodynamics, which states that heat flows from a region of higher temperature to a region of lower temperature.
• Option B: Temperature is a measure of the average kinetic energy of particles. A warmer cup of lemonade has a higher temperature, so the particles in the warmer cup have more kinetic energy than the particles in the colder cup.

Answer:

A. Energy from the hot table and warm air is transferred to the cold cups of lemonade.
B. The particles in the warmer cup of lemonade have more kinetic energy than the particles in the colder cup of lemonade.