Question

A metal cube has each side of length 1m loses all its energy at rate of 3000 watt if emmissivity is 0.4 find its temperature

Answer 1

A metal cube with each side of length

1 m loses all its energy at rate of

3000 watts/s, if the emissivity is 0.4. Find

its temperature.

[Given : σ = 5.67 × 10–8 J/m2

sK4

Given :

l = 1 m

A = 6l

2 = 6(1)2

= 6 m2

e = 0.4

σ = 5.67 × 10–8 J/m2

= 5.67 × 10–8 W/m2K4

dt = 3000 watts

To Find :

T = ?

Formula :

dQ

dt = σ AeT4

Solution

∴ T4 =

dQ

dt

σAe

∴ T4 =

3000

5.67 10 6 0.4 –8 × × ×

=

500

5.67 10 0.4 –8 × ×

T 4 =

1000

5.67 0.8 10–8 × ×

∴ T = 1000

5.67 0.8 10

1 4 –8 × ×

= 10000 10

5.67 8

Hope this helps you ☺️☺️❤️❤️✌️✌️