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?

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 710 n/m. it is initially at rest on an inclined plane that is at an angle of θ = 23° with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is μk = 0.19. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. a) what is the block's initial mechanical energy? b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Give an example of a collision in real life. use the law of conservation of energy to describe the transfer of momentum. be sure and discuss the momentum before and after the collision occurs. you will need at least 3 sentences to thoroughly answer this question.

The voltage applied across a given parallel-plate capacitor is doubled. how is the energy stored in the capacitor affected?