Question

Velocity is a vector quantity which has both magnitude and direction. ... Net force is also a vector quantity which has both magnitude and direction. Using complete sentences, describe the net force acting upon the object during the course of the elliptical orbit. Comment on both the magnitude and the direction.

Answer 1

When the object is moving in the elliptical orbit, it means that the direction of its acceleration should be towards the two foci (plural of focus) of the ellipse to keep the elliptical motion. As force according to the Newton's second law: F = ma, the net force must be in the direction of the acceleration. As far as the magnitude of net force is concerned, you can use Newton's gravitational law to find its magnitude.

Answer 2

The net force on an object moving in an elliptical path is the gravitational force. The force vector always points towards the object being orbited by the object following the elliptical orbit. In the case of the sun and earth, the force vector will always point towards the sun

The exact magnitude of the force is given by Newton's law of universal gravitation. The formula to calculate the magnitude of this force is ,$F=\frac{GMm}{r^2}.$

In this formula $G$ is the universal gravitational constant, $r$ is the distance between the two objects, $M,m$ each represent the masses of the central object and the object orbiting it.  As a consequence we can tell that closer to the central object, the magnitude of the force will be larger than further away from the object.