Question

the temperature of a piece of metal is raised from 27°c to 51°c .the rate at which metal radiates energy increases nearly​

Answer 1

according to Stefan's law radiation energy is directly proportional to (temperature)⁴

i.e., $E\propto T^4$

or, E = kT⁴ , here k is proportionality constant.

initially, T = 27° C = 27 + 273 = 300K

so, $E_i$ = k(300)⁴ = 81 × 10^8 k

finally, T = 51°C = 51 + 273 = 324K

so, $E_f$ = k(324)⁴ = 110.2 × 10^8 k

change in energy , ∆E = (110.2 - 81) × 10^8 k = 29.2 × 10^8k

percentage increases in energy = 29.2 × 10^8k/81 × 10^8k × 100

= (2920)/81

= 36.04 %

Answer 2

Answer:

          36.04 %

Explanation:

E = kT⁴ , here k is proportionality constant.

initially, T = 27° C = 27 + 273 = 300K

so,  = k(300)⁴ = 81 × 10^8 k

finally, T = 51°C = 51 + 273 = 324K

so,  = k(324)⁴ = 110.2 × 10^8 k

change in energy , ∆E = (110.2 - 81) × 10^8 k = 29.2 × 10^8k

percentage increases in energy = 29.2 × 10^8k/81 × 10^8k × 100

= (2920)/81

= 36.04 %