Question

which best describes heat?

• energy that decreases as a car slows to a stop
• energy that is carried by electric and magnetic fields
• energy that increases as a book is lifted to a higher shelf
• energy that flows from a hot mug of tea to a cold hand

Explanation:

Define heat in thermodynamics

Heat is energy transferred between systems or surroundings due to a temperature difference.

Analyze the first option

"energy that decreases as a car slows to a stop" describes kinetic energy converting to thermal/internal energy.

Analyze the second option

"energy that is carried by electric and magnetic fields" describes electromagnetic radiation.

Analyze the third option

"energy that increases as a book is lifted to a higher shelf" describes gravitational potential energy.

Analyze the fourth option

"energy that flows from a hot mug of tea to a cold hand" describes thermal energy transfer driven by a temperature gradient, which is the definition of heat. This relates to the Definition of Enthalpy as enthalpy changes are measured through heat flow at constant pressure.

Answer:

• energy that decreases as a car slows to a stop
• energy that is carried by electric and magnetic fields
• energy that increases as a book is lifted to a higher shelf
• energy that flows from a hot mug of tea to a cold hand (Correct answer)