Unit 4 inertia

Newton's first law of motion states that: an object at rest stays at rest while an object in motion stays in motion with the same speed an the same direction unless an unbalanced force is acting upon it. Inertia is the resistance an object has to change in its state of motion. So theoretically an object in motion, if there were no unbalanced forces acting upon an object and the ground it was on was frictionless, would keep on moving in the same direction forever. An object would only stop by coming in contact with a friction surface, hitting another object, or contacting another unbalanced force. Objects at rest will only move if a force pushed or pulled it, therefore, an object at rest would stay at rest forever. In this picture on the side, the ice skaters would keep on moving if the ice was frictionless. But because the ice has friction, the skaters stop after a short period of time, and that is why they need to push their skates off the ice to move forward. If the ice was frictionless, the skaters would keep moving till they hit the sides, or they wouldn't be able to move at all if they were in the middle of the ice at rest (unless they threw stuff in the opposite direction.