COURSE TITLE: HEAT TRANSFER-II (DURATION 1 HOUR)

QUESTION:

A sphere with a diameter of 30 mm is initially at a temperature of 450 oC, then released into a medium with a temperature of 95 oC;
a) the time required for the temperature of the sphere to drop to 150 oC,
b) the time needed to equalize the temperature,
c) calculate the equilibrium temperature.

k = 35 W / mK,
h = 10 W / m^2K
ρ= 7800 kg / m^3
C = 460 J / kg. k