please complete

Newton's First Law - The Law of Inertia When the sum of the forces exerted on a system is zero, the system will maintain constant velocity. This includes a constant velocity of zero (remaining at rest), or a constant nonzero velocity (moving at a constant speed in a straight line). Part 1 - Describing Inertia http://www.islephysics.net/pt3/experiment.php?topicid=3&exptid=27 1. Watch the video of the woman on Rollerblades and describe how she demonstrates that "when the sum of the forces exerted on a system is zero, the system will remain at rest" (keep in mind that the woman is the system). 2. What external force was applied to put the woman in motion? 3. Now describe how the woman demonstrates when the sum of the forces exerted on a system is zero, the system will maintain a constant velocity