Two identical loudspeakers are driven in phase by a common oscillator at 850 hz and face each other at a distance of 1.26 m. locate the points along the line joining the two speakers where relative minima of sound pressure amplitude would be expected. (take the speed of sound in air to be 343 m/s. choose one speaker as the origin and give your answers in order of increasing distance from this speaker. enter 'none' in all unused answer boxes.)

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

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?

Madison pushes with a 210-n horizontal force on a 24-kg crate of coffee resting on a warehouse floor. the force of friction on the crate is 74 n. what is the acceleration?