A5 cm diameter upside-down piston-cylinder device contains 0.04 kg of an ideal gas at equilibrium at 100 kpa, 300 k, occupying a volume of 0.5 m3. determine (a) the gas density in kg/m3, and (b) the specific volume in m3/kg. (c) a mass is now hung from the piston so that the piston moves down and the pressure decreases. determine the mass in kg necessary to reduce the pressure inside to 50 kpa after the piston comes to a new equilibrium. assume the piston to be weightless. (data supplied: g = 9.81 m/s2; outside pressure: 100 kpa; univ gas constant = 8.314 kj/(kmol-k).[solution] [discuss]

On a horizontal frictionless surface, a small block with mass 0.200 kg has a collision with a block of mass 0.400 kg. immediately after the collision, the 0.200 kg block is moving at 12.0 m/s in the direction 30° north of east and the 0.400 kg block is moving at 11.2 m/s in the direction 53.1° south of east. use coordinates where the +x-axis is east and the +y-axis is north.(a) what is the total kinetic energy of the two blocks after the collision (in ) what is the x-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your ) what is the y-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your answer.)