Question

question 8 of 20
which scenario is an example of the transfer of thermal energy by conduction?
a. water in the entire pot is warmed when it is heated from the bottom.
b. a person can feel warmth from hot sand before stepping on it.
c. a frozen lake melts under the sun.
d. an ice cube melts in a persons hand.

Explanation:

• Option A: This is an example of convection. Convection is the transfer of heat through the movement of fluids (liquids or gases). When water in a pot is heated from the bottom, the hot water rises and cooler water sinks, creating a circular motion (convection currents) that warms the entire pot.
• Option B: Feeling warmth from hot sand before stepping on it is an example of radiation. Radiation is the transfer of heat in the form of electromagnetic waves. The hot sand emits infrared radiation (a form of electromagnetic wave), and this radiation travels through the air (which is a poor conductor of heat) to reach the person.
• Option C: A frozen lake melting under the Sun is an example of radiation. The Sun emits electromagnetic radiation (including visible light and infrared radiation). This radiation travels through space and the Earth's atmosphere and is absorbed by the ice in the lake, causing it to melt.
• Option D: When an ice cube melts in a person's hand, heat is transferred from the person's hand (a warmer object) to the ice cube (a cooler object) through direct contact. Conduction is the transfer of heat through direct contact between particles of a substance (in this case, the particles in the person's hand and the ice cube).

Answer:

D. An ice cube melts in a person's hand.