Astopped pipe 1.00 m in length is filled with helium at 20∘c (speed of sound 999 m/s). when the helium in this pipe vibrates at its third harmonic frequency, it causes the air at 20∘c (speed of sound 344 m/s) in a nearby open pipe to vibrate at its fifth harmonic frequency. what is the frequency of the sound wave in the helium in the stopped pipe? express your answer with the appropriate units.

Atriangle with equal sides of length 10 cm has -2.5-nc charged objects at each corner. part a determine the direction of the electrical force exerted on the object at the top corner due to the two objects at the horizontal base of the triangle. determine the direction of the electrical force exerted on the object at the top corner due to the two objects at the horizontal base of the triangle. horizontally rightward vertically downward vertically upward horizontally leftward