Question

Two sphere of radii 8 cm and 2 cm are cooling.Their temperatures are 127 and 527 degree respectively. Find the ratio of energy

Answer 1

The Temperature T1 = 127°C = 273 + 127 K = 400 K

And another Temperature T2 = 527°C = 273 + 527 K = 800 K  

Now, The total energy radiated by the body Q = Aσ0, T4 t

=> Q/Tt A∝     Where A=4πr²

Q1/Q2 = (r1/r2)² (t1/t2)4 = (8/2)²(400/800) 4

(4)²×(1/2)4 = 16×1/16 =1

Therefore the energy radiated at the same time is = 1