A point particle of mass Mattached to one end of a massless rigid non- conducting rod of length L. Another point particle of the same mass is attached to the other end of the rod. The two particles carry charges +q and 6-9 respectively. This arrangement is held in a region of a uniform electric field E such that the rod makes a small angle 0 (say of about 5 degrees) with the field direction. Find an expression for the minimum time needed for the rod to become parallel to the field after it is set free. -9 Ꮎ +9 -E

A point particle of mass Mattached to one end of a massless rigid non- conducting rod of length L. Another point particle of the same mass is attached to the other end of the rod. The two particles carry charges +q and 6-9 respectively. This arrangement is held in a region of a uniform electric field E such that the rod makes a small angle 0 (say of about 5 degrees) with the field direction. Find an expression for the minimum time needed for the rod to become parallel to the field after it is set free. -9 Ꮎ +9 -E