Lesson 1: Force
In 1666 Newton did his early work on his Three Laws of Motion. To this day, those laws still hold true. There has been some allowances for really big things (like the cosmos) and for really small things (like the atom). Other than that, Newton’s Law’s are pretty much dead on.
Newton’s Laws are all they used to get the first man to the moon. They are an amazingly powerful and wonderful area of physics. I like them because evidence of them is everywhere. If something moves or can be moved, it follows Newton’s Laws. You can’t sit in a car, walk down the road, drink a glass of milk, or kick a ball without using Newton’s Laws. I also like them because they are relatively easy to understand and yet open up worlds of answers and questions. They are truly a foundation for understanding the world around you.
If I asked you to define the word force, what would you say?
You probably have a feeling for what force means, but you may have trouble putting it into words. It’s kind of like asking someone to define the word “and” or “the”. Well, this lesson is all about giving you a better feeling for what the word force means. We’ll be talking a lot about forces in many lessons to come. So, pay attention! The simplest way to define force is to say that it means a push or a pull like pulling a wagon or pushing a car. That’s a correct definition, but there’s a lot more to what a force is than just that.
Here are the highlights for Force:
1. A force is a push or a pull.
2. There are four fundamental forces. In order of strength they are strong nuclear force, electromagnetism, weak nuclear force, and gravity.
3. A force field is an invisible area around an object within which that object can cause other objects to move.
4. A force field can be attractive (pull an object towards it) or repulsive (push an object away).
5. The closer something gets to the object causing the force, the stronger the force gets on that object. This is the inverse-square law.
6. The four basic force fields are gravity, magnetic, electric, and electromagnetic.
7. An object will be pushed or pulled in the direction in which the overall net force is acting on it.
8.The net force is the sum of all the forces on an object.
Let’s take a look by reading more about Forces.