Aparallel-plate capacitor has plates of area a. the plates are initially separated by a distance d, but this distance can be varied. the capacitor is connected to a battery. what should the plate separation be if you want to halve the energy density?

Which type of circuit is becoming more common in residential electrical design and construction? a. hazardous-area circuit b. three-phase circuit c. 480-volt circuit d. communication circuit

Argon is adiabatically compressed from an initial volume of 16 liters to a final volume of 2 liters. by what factor do the following quantities change? do they increase or decrease? (a) the rms speed (b) the thermal energy of the gas (c) the molar specific heat cv (d) the pressure

Consider a double atwood machine constructed as follows: a mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. the other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. using two suitable generalized coordinates, set up the lagrangian and use the lagrange equations to find the acceleration of the mass 4m when the system is released. explain why the top pulley rotates even though it carries equal weights on each side.