Heat transfer can change an object's temperature. In this lesson, you will learn how the amount of transferred heat depends on mass, temperature change, and the material involved.
When an object gains heat, its temperature generally rises; when it loses heat, its temperature generally falls. For the relationships in this lesson, assume there is no phase change and no work is done on or by the system. Under these conditions, transferred heat changes the system's internal energy.
All flashcards
Specific heat
Heat required to change the temperature of one kilogram of a substance by one degree; it depends on the material and phase.
Heat-transfer equation
Q=mcΔT, where Q is transferred heat, m is mass, c is specific heat, and ΔT=Tf−Ti.
Heat capacity of an object
The product mc, which determines how much heat changes the object's temperature by one degree.
Thermal equilibrium
The state in which objects in thermal contact share the same temperature.
Signed heat transfer
With Q=mc(Tf−Ti), absorbed heat is positive and released heat is negative.
Quiz questions
What is thermal equilibrium for two objects in thermal contact?Answer: They have reached the same temperature.
For two objects in an insulated system with no phase change, how are their signed heat transfers related?Answer: Their signed heat transfers sum to zero.
Two materials in thermal contact undergo the same temperature change. What determines how much heat each absorbs?Answer: Each material's mass and specific heat.
When a hot object and a cold object exchange heat in an insulated system without a phase change, where does their final temperature lie?Answer: Between their two initial temperatures.
A material receives a fixed amount of heat. How does increasing its mass affect its temperature change, assuming its specific heat stays constant?Answer: Its temperature change becomes smaller.
Based on College Physics 2e by Paul Peter Urone, Roger Hinrichs (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.