An open vertical tube has water in it. A tuning fork vibrates over its mouth. As the water level is lowered in the tube, the seventh foss (zef86) – Homework 10, oscillations and waves 19-20 – dowd – (PriceEPHY11920 2) 5 resonance is heard when the water level is 55.25 cm below the top of the tube. 55.25 cm What is the wavelength of the sound wave? The speed of sound in air is 343 m/s. Answer in units of cm

The dipole moment of the water molecule (h2o) is 6.17x10^-30 c.m. consider a water molecule located at the origin whose dipole moment p points in the +x-direction. a chlorine ion ( of charge-1.60x10^-19c , is located at x=3.00x10^-9m . assume that is much larger than the separation d between the charges in the dipole, so that the approximate expression for the electric field along the dipole axis can be used. a) find the magnitude of the electric force that the water molecule exerts on the chlorine ion. b) what is the direction of the electric force. -x-direction or +x-direction c) is this force attractive or repulsive?