in a compound microscope the image formed by the objective lens is at a distance of 3cm from the eye lens. if the final image is at 25cm from the eye lens, calculate the focal length of the eye lens.

Wo audio speakers are placed on a vertical rail. speaker a is placed at head-level while speaker b is place at some variable height, \delta yδy, above speaker a. both speakers receive simultaneous input from a sine-wave generator so the speakers each produce a pure sinusoidal sound wave with a wavelength of 0.531 meters. calculate the lowest height that speaker b can be placed above speaker a to produce a minimum of sound heard by person standing \delta x = 7.86δx=7.86 meters directly in front of speaker a.

Calculate the capacitance of a system that stores 2.0 x 10^-10c of charge at 100.0 v. use c=q/v. a. 2.0 x 10^-12 f b. 2.0 x 10^-8 f c. 5.0 x 10^11 f d. 5.0 x 10^7 f

Hen a gfci receptacle device is installed on a 20-ampere branch circuit (12 awg copper), what is the minimum volume allowance (in cubic inches) required for conductor fill for each conductor in the outlet box?