A parallel plate capacitor has a separation of 2x10 m and free space between the plates. A 10 V battery is connected across the plates and then removed without disturbing the charge on the plates. The plates are now allowed to come together toa separation of 10% m without disturbing the charge on the plates. Fringing fields can be ignored. A) What is the voltage across the plates? B) How has the energy stored in the capacitor changed?

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2