Newton's Three Laws of Motion

By: Kendall Talton

Newton's First Law of Motion

Newton's first law is sometimes referred to as the Law of Inertia, or an object's tendency to resist a change in motion. It says, "An object in motion will stay in motion unless acted upon by an outside force, and an object at rest will stay at rest unless acted upon by an outside force." So, the speed for the objects at rest or in motion would look like this starting with the object in motion: v 0 m/s, while an object as rest's speed looks like this: v = 0 m/s. The not equal symbol, implies that the object DOES NOT have a speed of 0 m/s, but instead that the speed is greater than 0 m/s. Which means that it is traveling even if it's speed 0.001 m/s. That's really slow, but it's still moving. It's all because of Newton's First Law of Motion. Be sure to take a look at an example in the video below. If you watch, you'll notice that the golf balls all stay in place after broom hits the board. But since there isn't anything holding golf balls up anymore, they fall into the cups of water.
Newton's 1st Law of Motion

Newton's Second Law of Motion

The first law of motion is the longest law to say, so it can be a bit of a mouthful when saying it. Which is why I like Newton's Second Law a little more than the first. The Second Law says, "F = ma." Which really means: force equals mass times acceleration. Since that can be a little confusing, let's do an example. Let's say we have an object that has a mass of 10 kilograms and it's moving 10 m/s², which would be it's acceleration, or the rate of change of time. Since force equals mass times acceleration, we would set the equation to look like this: F = 10 kg. times 10 m/s². The force would then equal 100 kg times m/s². It's that easy. Now that we've tackled the first 2 laws, let's finish with the third and final Law of Motion. Check the video below if you want another example.
force equals mass time acceleration

Newton's Third Law of Motion

Newton's Third Law is perhaps the easiest Law to remember because we can tell it is happening on a daily basis by actually seeing it. Because you can't see gravity pulling an object to the ground, and you don't want to calculate the force it takes to move an object with a certain mass. The Third Law states, "For every action, there is an equal and opposite reaction." This is easy to see in many places. So here's a couple examples: We have 2 cars, they are the exact same make and model, and weigh exactly the same. One is moving and one isn't. Car A (the moving car) hits Car B (stationary car), Car B with bounce off of Car A going the exact same speed as Car A until gravity and air, sliding, and rolling friction stop it. The second example is Newton Balls. I can't really explain it, except to say that the balls swing and hit each other as momentum transfers energy from ball to ball constantly making them swing. It's simple physics, and now that you know, you can go spread your knowledge with others and educate them on Newton's Three Laws of Motion. There's also a video below that show action and reaction. When the person ties the metal block to the launching device, they are making potential energy, or stored energy, that eventually turns into kinetic energy, energy in motion, that flings the block and the launching device to opposite sides of the container.
Newton's 3rd Law