Answer:
The answer is below
Explanation:
Given that:
ρ = 800 kg/m3, c = 600 J/kg-K, k = 40 W/m-K, Initial temperature = Ti = 1150,
Environment temperature = T = 450 K, Final temperature = T∞ = 325 K
Diameter = 10 mm = 0.01 m, A = 6
The estimated time for cooling process (t) is given as:
[tex]t=\frac{\rho dc}{hA} ln\frac{T_i-T_\infty}{T-T_infty}=\frac{7800*0.01*600}{25*6} ln\frac{1150-325}{450-325}\\ \\t=589\ s\\t=0.1635\ h[/tex]
The estimated cooling time is 589 s
