A 2.98 X 102-kg crate is being pulled across a horizontal surface by a force F which makes an angle of 35.90 above the horizontal. Suppose that the coefficient of kinetic friction is 0.222, what should the magnitude of F be so that the net work done by it and the kinetic frictional force is zero?

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?