A ruby crystal rod operates as an amplifier for the radiation at λ! = 694.3 nm that coincides with the central wavelength of the rubyâs atomic transition. The quantum efficiency of the transition is close to 100 %, the spontaneous emission lifetime is t!" = 4.3 ms, and the transition cross section at the central wavelength is ð(λ!) = 2.5 x 10!!" cm!.
a) Assuming a homogeneously broadened Lorentzian transition lineshape, calculate the transition bandwidth Îv (FWHM).

Apump is used to circulate hot water in a home heating system. water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. the inlet pressure and temperature are 14.7 lbf/in.2, and 180°f, respectively; at the exit the pressure is 60 lbf/in.2 the pump requires 1/15 hp of power input. water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 btu/lb or. neglecting kinetic and potential energy effects, determine the temperature change, in °r, as the water flows through the pump.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2