Arow of seats is parallel to a stage at a distance of 90 m from it. at the center and front of the stage is a diffraction horn loudspeaker. this speaker sends out its sound through an opening that is like a small doorway with a width d of 0.070 m. the speaker is playing a tone that has a frequency of 4.00 x 10 hz. the speed of sound is 343 m/s. what is the separation between two seats, located near the center of the row, at which the tone cannot be heard?

Why there is no inductive reactance in dc circuits

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants

Diego kicks a soccer ball from the end line. his fellow students time and mark the soccer ball as it moves down the field. the graph represents the ball's progress. based on the graph, during what time is the velocity constant and positive?