Physical Science
January 23, 2012

First Law of Motion

The velocity of a body that remains constant unless another force acts upon it is the first law of motion. The first law of motion can be associated with inertia, which is a property of matter that remains at rest unless acted upon by an external force. The movie taught me that an object at rest would stay at rest unless there in another force exerted on the object. Inertia and mass are very similar and are commonly confused. Even though they are very alike they have their differences. Inertia is the resistance of motion and mass is the amount of matter that an object contains. The video taught me that everything that consists of inertia is sluggish or lazy and tends to stay at rest. Unlike inertia, mass when moving tends to stay in motion. Mass depends on inertia just as inertia depends on mass. The more inertia and object has, the more mass it contains. An object with large amounts of mass has a better chance to resist changes in its state. For example, if a large boulder is rolling down a hill, it is going to remain in motion until something with greater mass stops it. The first law of motion written by Newton also states that an object in motion will stay in a straight line of motion unless unbalanced or external force acts upon it. When a plane is flying straight it will continue flying straight unless a large gust of wind or cloud is pushing on it. The pilot has control over the plane and is able to direct its motions, but he still faces resistance from wind pushing the plane backward. When landing the plane, inertia is in action because of the brakes that the pilot is using. People inside the plane are still moving at the same pace as the plane was, but are being held back by their seatbelts. Without the seatbelts passengers would be pushed out of their seats because they are being affected by the speed of the plane and it stopping. Inertia acts upon everything that is physically touching another object. When sliding upon the floor you will eventually stop because of inertia.