A 0.5 kg block B slides without friction inside a slot cut in arm OA which rotates in a vertical plane. the rod has a constant angular acceleration theta = 10 rad/s^2. knowing that when theta = 45 and r = 0.8 m the velocity of the block is zero, determine at this instant (a) the force exerted on the block by the arm, (b) the relative acceleration of the block with respect to the arm

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.