A solid cylinder of radius r1=2.5cm,length h1=5.0cm,emissivity 0.85,and tenmpreature 30 degree is suspended in an environment of temperature 50 degree.(a)What is the cylinder's net thermal radiation transfer rate P1?(b)If the cylinder is stretched until its radius is r2=0.5cm,its net thermal radiation transfer rate becomes P2.What is the ratio P2/P1?