What is the value of coefficient of absorption for a perfect black body?

What is coefficient absorption ?

What is perfectly black body ?

The coefficient of absorption of the thermal radiation of black body is

What is the sum of coefficients of absorption, reflection, and transmission of the body is.......

A body of 37 kg rests on a rough horizontalsurface. The minimum horizontal force required to just start the motion is 68.5 N. In order to keep the body moving with a constant velocity a force of 43 N is needed. What is the value (i) of the coefficient of static friction (ii) the coefficient of kinetic friction?

Emissive power of a perfectly black body

What emissive power of perfectly black body ?

A body of mass 37 kg rests on a rough horizontal surface. The minimum horizontal force required to just start the motion is 68.5 N. In order to keep the body moving with constant velocity, a force of 43 N is needed. What is the value of coefficient of static friction?

A body of mass 37 kg rests on a rough horizontal surface. The minimum horizontal force required to just start the motion is 68.5 N. In order to keep the body moving with constant velocity, a force of 43 N is needed. What is the value of coefficient of kinetic friction?

Heat energy is incident on the surface at the rate of 1000 J/min. If coefficient of absorption is 0.8 and coefficient of reflection is 0.1 then heat energy transmitted by the surface in 5 minute is