1. Snapshot 1 Consider the hover disk sitting on the floor. Hover Disk Earth Floor Force Diagram (Free-Body Diagram) Constant Velocity Balanced Forces

2. Snapshot 2 The hover disk is moving to the right while on. Hover Disk Earth Floor Constant Velocity Balanced Forces

3. Snapshot 3 The hover disk is sliding to the right while off. Hover Disk Earth Floor Changing Velocity Unbalanced Forces

4. Snapshot 4 The hover disk is pulled to the right while on. Hover Disk Earth Floor Changing Velocity Unbalanced Forces String

5. Do you see a pattern between the type of motion and whether or not the forces are balanced? Constant Velocity Balanced Forces Snapshot 1 Constant Velocity Balanced Forces Snapshot 2 Changing Velocity Unbalanced Forces Snapshot 3 Changing Velocity Unbalanced Forces Snapshot 4

6. Sir Isaac Newton (December 25 th, 1642-1727) Newton’s First Law of Motion – Objects move with constant velocity when the forces are balanced and move with changing velocity when the forces are unbalanced.