The drawing shows a loudspeaker a and point c, where a listener is positioned. a second loudspeaker b is located somewhere to the right of loudspeaker a. both speakers vibrate in phase and are playing a 67.6-hz tone. the speed of sound is 343 m/s. what is the closest to speaker a that speaker b can be located, so that the listener hears no sound? (assume |ac| = 4.00 m.)

Aconstraint-based modeler is used to create a gear cluster assembly by inserting modeled bicycle gear cogs and spacers onto a splined hub. axial and radial alignment of the elements is critical to maintaining an accurate model. define a sensible base point to use when adding individual cogs (gears) to the assembly.

4–66. the force of f = 30 n acts on the bracket as shown. determine the moment of the force about the a-a axis of the pipe if a = 60, b = 60, and g = 45. also, determine the coordinate direction angles of f in order to produce the maximum moment about the a-a axis. what is this moment?

Continuous tubing is produced in a plastic extrusion operation through a die orifice whose outside diameter = 2.0 in and inside diameter = 1.5 in. the extruder barrel diameter = 5.0 in and length = 12 ft. the screw rotates at 50 rev/min; it has a channel depth = 0.30 in and flight angle = 16°. the head pressure has a value of 350 lb/in2 and the viscosity of the polymer melt is 90 x 10-4 lb-sec/in2. under these conditions, what is the production rate in length of tube/min, given that the die swell ratio is 1.25.