A balloon uses hot air to provide its lifting capacity. Prior to its release, it is tethered to the ground by a steel cable. If the gondola, weights, passengers, and material weigh 2000 lb, determine the tension in the cable when the balloon is inflated as a sphere having a diameter of 60 ft. Assume that the hot air has a specific weight of 0.040 lb/ft3 and ambient air has a specific weight of 0.070 lb.ft3