A marble launcher is set up to launch marbles in the horizontal direction. It has a spring constant of 190 N/m and a marble of mass 0.0059 kg is loaded and compresses the spring 0.071 m. What is the speed of the marble when it exits the launcher?

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.