9. A 1.00 kg mass is placed at the free end of a compressed spring. The force constant of
the spring is 115 N/m. The spring has been compressed 0.200 m from it neutral position.
It is now released. Neglecting the mass of the spring and assuming that the mass is
sliding on a frictionless surface, how fast will the mass move as it passes the neutral
position of the spring?

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?