The laser pointer emits light because electrons in the material are excited (by a battery) from their ground state to an upper excited state. when the electrons return to the ground state, they lose the excess energy in the form of 537-nm photons. what is the energy gap between the ground state and excited state in the laser material?

Why cooking gas has a typical smell

Amanometer is used to measure the air pressure in a tank. the fluid used has a specific gravity of 1.25, and the differential height between the two arms of the manometer is 34 in. if the local atmospheric pressure is 12.7 psia, determine the absolute pressure in the tank for the cases of the

We want to calculate the total metabolic heat generated by a singing canary taking into account heat transfer by radiation, convection and exhaling air. the air temperature is 20 oc, canary’s body internal and surface temperature is 33oc, external body surface convective heat transfer coefficient is 25.2 w/m2 .k, temperature difference between the inhaled and exhaled air is 4.3 oc, the ventilation rate is 0.74 cc of air per second, specific heat of air is 1.0066 kj/kg.k and density of air is 1.16 kg/m3 . assume the canary’s body to be a cylinder with 7 cm diameter and 9 cm length, and heat exchange is from the side as well as the top and bottom of cylinder. calculate 1) the net rate of heat lost by radiation, assuming heat gained by the bird through radiation from the surroundings is 11.5 w; 2) rate of heat transferred by convection to the surrounding air; 3) rate of heat transferred in the exhaling air without considering any internal evaporation; 4) total metabolic power.