If the gravitational forces pulling the rocks towards earth would have been equal magnitude, which rock would have landed on earths surface first? 1kg or 2kg or both

Consider two concentric spheres forming an enclosure with diameters of 12 cm and 18 cm the spheres are maintained at uniform temperatures ti-50°c and t2 = 250°c and have emissivities .45 and .8, respectively. determine the net rate of radiation heat transfer between the two spheres per unit surface area.

Areheat rankine cycle operates with water as the working fluid. steam enters the first turbine at 8 mpa and 450°c and exits at 0.8 mpa. it is then reheated to 400°c before entering the second turbine, where it exits at 10 kpa. if the amount of work into the pump is 8.04 kj/kg and the net work per cycle produced is 1410.25 kj/kg, determine the thermal efficiency of the cycle.

Steam enters a converging nozzle at 3.0 mpa and 500°c with a negligible velocity, and it exits at 1.8 mpa. for a nozzle exit area of 32 cm2, determine the exit velocity, mass flow rate, and exit mach number if the nozzle: is isentropic (a) (b) has an efficiency of 94 percent