Lesson Six: Newton's First Law of Motion
Definition: Newton’s First Law of Motion says that an object at rest will remain at rest unless acted on by an external force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an external force. This law is often called "the law of inertia". |
More simply stated, things want to keep on doing what they are already doing. If you kick a ball, it will keep moving unless it is stopped by some outside force. At the same time, it states that if something is in a resting position, it will always be in that position unless an outside force is applied to it to make it change its position. Look at the soccer ball example to the left. The ball stays put on the ground until acted on by the force of a foot kicking it. The ball continues in motion until it is acted upon by an external force, the net, stopping the ball.
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Take a look at the following website. It provides further explanation of Newton’s First Law and gives picture representations of exactly how this law works.
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Let’s take a look at some examples of everyday applications of Newton’s First Law. This may help you better understand how this applies to the world around you.
1. When a bus suddenly starts, the passengers sitting or standing tend to fall backward.
2. A soccer ball will not move until a player kicks it.
3. A rider on a running horse is thrown forward when the horse stops suddenly, as the person continues to move even thought the horse has stopped.
4. A moving bowling ball hits the pins causing them to fall down.
5. Your seatbelt stops you from hitting the windshield when your car stops fast.
6. A baseball continues to roll until something hits it.
7. A dish left in the sink remains there until someone moves it.
2. A soccer ball will not move until a player kicks it.
3. A rider on a running horse is thrown forward when the horse stops suddenly, as the person continues to move even thought the horse has stopped.
4. A moving bowling ball hits the pins causing them to fall down.
5. Your seatbelt stops you from hitting the windshield when your car stops fast.
6. A baseball continues to roll until something hits it.
7. A dish left in the sink remains there until someone moves it.
Take a look at the link to NASA below. It provides some excellent examples of Newton's first law involving aerodynamics. Click on the blue links to see the picture model change, giving you a description of different airplane scenarios where the first law of motion is applied.