A 2.5 cm sphere is maintained at 50?C in an air stream or a water stream, both at 20?C and 2 m/s velocity. Compare the rate of heat transfer and the drag on the sphere for both fluids.GIVENA sphere in an air stream or a water streamSphere diameter (D) = 2.5 cm = 0.025 mSphere temperature (Ts) = 50?CFluid temperature (Tf) = 20?CFluid velocity (U??) = 2 m/sASSUMPTIONSRadiation is negligibleFrom Appendix2

Alr or Water Tm 20C U - 2 m/s D-2.5 cm Water Fluid Air Table Number 13 27 Density at 20C, p (kg/m) Thermal conductivity at 20C, k (W/(m K)) Kinematic Viscosity at 20C, v x 10 (m/s) 998.2 1.164 0.0251 0.597 15.7 1.006 Prandtl number at 20C, Pr 0.71 7.0 x 10 ((Ns)/m?) x 10 ((Ns)/m) Absolute viscosity at 20C, 18.240 993 Absolute viscosity at 50C, 19.515 555.1