masses of 10 and 15 kilograms to be subjected to the force F to move with a constant acceleration of 4 m / s in the upper level, the kinetic coefficient of 0.25 is determined. Find the magnitude of the reaction force F with mass 10 kg. Acts on a mass of 15 kg

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s.part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.