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]

Note: the following questions are unrelated to the balmer series or the martian. refer to your course notes. a sun-sized star will spend most of its lifetime as a: white dwarf b. red giant c. protostar d. main-sequence star

How have the competing explanations' experiments on atoms affected the development of the atomic model?

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!