Rate of heat flow

- The rate of heat flow between two systems is measured in watts (joules per second).

The formula for the rate of heat flow is

{\frac {\Delta Q}{\Delta t}}=-KA{\frac {\Delta T}{x}},

where ${\frac {\Delta Q}{\Delta t}}$ is the rate of heat flow, $-K$ is the thermal conductivity factor, $A$ is the surfaces area, $\Delta T$ is the change in temperature, and $x$ is the thickness of the material ( ${\frac {\Delta T}{x}}$ is called the temperature gradient and is always negative because the heat always flows from the higher temperature to the lower).

Rate of heat flow

See also