Question: A metal ball of radius 0.1 m at a uniform temperature of 90°C is left in air at 30°C. The density and the specific heat of the metal are 3000 kg/m3 and 0.4 kJ/kg.K respectively. The heat transfer co-efficient is 50 W/m2.K Neglecting the temperature gradients inside the ball, the time taken (in hours) for the ball to cool to 60°C is
[A].
555
55.5
0.55
0.15
[A].
[B].
[C].
[D].
Answer: Option D
Explanation:
No answer description available for this question.