A light ray is incident from air into glass (ng = 1.52) then onto water (nw= 1.33). The wavelength of light in air (na= 1) is air = 500 nm and it travels at a speed c = 3 x 108 m/s. The wavelength of light, A, and its frequency, f, in water, are, respectively: (a) 376 nm, 6 x 10¹4 Hz.
(b) 376 nm, 8 x 10¹¹ Hz
(c) 500 nm, 6 x 10¹4 Hz
(d) 500 nm, 8 x 10¹¹ Hz​

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?