question_answer 45)

                  What is the direction of areal velocity of the earth around the sun?

Answer:

                  Areal velocity, \[\frac{d\vec{A}}{dt}=\,\frac{{\vec{L}}}{2m},\] where \[\vec{L}\] is the angular momentum of the earth.                 Since, direction of \[\vec{L}\] is perpendicular to the plane containing the sun and the earth, so direction of areal velocity is also perpendicular to the plane containing the earth and the sun.