A diffuse, spherical object of diameter and temperature 9

Chapter , Problem 12.87

(choose chapter or problem)

A diffuse, spherical object of diameter and temperature 9 mm and 600 K, respectively, has an emissivity of 0.95. Two very sensitive radiation detectors, each with an aperture area of 300 106 m2 , detect the object as it passes over at high velocity from left to right as shown in the schematic. The detectors capture hemispherical irradiation and are equipped with filters characterized by 0.9 for 2.5 m and 0 for 2.5 m. At time t1 0, detectors A and B indicate irradiations of GA,1 5.060 mW/m2 and GB,1 5.000 mW/m2 , respectively. At time t2 4 ms, detectors A and B indicate irradiations of GA,2 5.010 mW/m2 and GB,2 5.050 mW/m2 , respectively. The environment is at 300 K. Determine the velocity components of the particle, vx and vy. Determine when and where the particle will strike a horizontal plane located at y 0. Hint: The object is located at an elevation above y 2 m when it is detected. Assume the objects trajectory is a straight line in the plane of the page. Recall that the projected area of a sphere is a circle. Detector A