Answer:
129.6 seconds
Step-by-step explanation:
Given that :
α = 0.0002°c-1
θ1 = 20°C
θ2 = 5°C
Time t = one day ; Converting to seconds ; number of seconds in a day ; (24 * 60 * 60) = 86400 seconds
Let dT= change in time
Using the relation :
dT = 0.5* α * dθ * t
dθ = (20 - 5) = 15°C
dT = 0.5 * 0.0002 * 15 * 86400
dT = 129.6 seconds