Discussion Forum

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

Answer:

Explanation:

Given, rate of  heat energy (Q₁)= 1000 J /min

 We know that ,

 1=a+r+t

 Here, coefficient of absorption (a)= 0.8

 Coefficient of reflection (r)= 0.1

 Now,

   1=0.8+0.1+t

  t=1-0.9

 t=0.1

 The rate of transmitted heat energy in 5 min , 

Q_r  = $\theta _{i}$ $ \times t \times$ (time) =1000 x 0.1 x 5= 500 J