Only a fraction of the electrical energy supplied to a tungsten light bulb is converted to visible light. the rest of the energy shows up as infrared radiation (i. e., heat). a 75-w light bulb converts 15.0% of the energy supplied to it into visible light. assuming a wavelength of 550 nm, how many photons are emitted by the light bulb per second? (recall 1 w = 1 j/s)

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg