Heat radiations propagate with the speed of

The velocity of heat radiation in vacuum is

For an opaque body,the coefficient of transmission is:

Three identical metal spheres (of same surface area) have red,black,and white colors and they are heated up to the same temperature. They are allowed to cool. Arrange them from maximum rate of cooling to minimum rate of cooling.

If the absorption and reflection coefficients of a surface of a body are $0.4$ and $0.6$ respectively,then

$A$ body has a transmission power of $1/6$ and a reflection power of $1/3$. Find its absorption power.