Investigate Thermal Energy Transfer Mechanisms - Physics

$Q=2.52\times 10^4,\text{J}$. Using $Q=mc\Delta T$: $Q=2.0\times 4200\times 3.0=25200,\text{J}$.

$\Delta T=2.5,\text{K}$. Rearranging $Q=mc\Delta T$: $\Delta T=\frac{500}{0.20\times 1000}=2.5,\text{K}$.

A lid on a pot. Lids trap heated air, preventing convective heat loss.

State where objects in contact have the same temperature. No net heat flow occurs when temperatures equalize.

Convection. Density differences drive fluid circulation and energy transport.

Dull black paint. Dark, rough surfaces absorb and emit radiation better than shiny ones.

Conduction, convection, radiation. These are the only three ways thermal energy moves between objects.

Thermal energy transfer by particle collisions in matter. Direct contact allows kinetic energy to pass between adjacent particles.

Thermal energy transfer by bulk fluid motion from density changes. Hot fluid expands, becomes less dense, and rises while cool fluid sinks.

Energy transfer by electromagnetic waves (mainly infrared). All objects emit EM waves; hotter objects emit more infrared.

Radiation. Only electromagnetic waves can travel through empty space.

Mobile electrons transfer energy efficiently. Free electrons move easily and carry kinetic energy rapidly.

Same temperature, so net heat transfer is $0$. Equal temperatures mean no net energy flow between objects.

$Q>0$. Positive $Q$ means energy flows into the system.

$Q=mc\Delta T$. Relates heat to mass, specific heat capacity, and temperature change.

$Q=mL$. $L$ is latent heat; temperature stays constant during phase transitions.

From the hotter object to the colder object. Heat always flows from higher to lower temperature spontaneously.

$P=e\sigma AT^4$. $e$ is emissivity, $\sigma$ is Stefan-Boltzmann constant.

$P_{net}=e\sigma A\left(T^4-T_{env}^4\right)$. Accounts for both emission and absorption from surroundings.

Fluids (liquids and gases). Only fluids can flow and create convection currents.

Conduction. Heat travels through the spoon by particle-to-particle contact.

Radiation. Only electromagnetic waves can travel through empty space.

Transfer by bulk motion of a fluid (liquid or gas). Heated fluid expands, becomes less dense, and rises, carrying energy.

Shiny foil wrap. Reflective surfaces have low emissivity, reducing radiation exchange.

Radiation. Solar energy reaches Earth as electromagnetic waves through vacuum.

Convection. Density-driven fluid motion creates circulation patterns.

Conduction. Heat travels through the metal by particle-to-particle contact.

Buoyancy from density differences. Temperature differences create density variations that drive flow.

Matte black. Black surfaces have high emissivity; shiny surfaces reflect radiation.