Question

When should we use the three laws of motion ?

Answer 1

they are used in many application where frame of referance is neutonian

Newton's law are very important because they tie into almost everything we see in everyday life. These laws tell us exactly how things move or sit still, like why you don't float out of bed or fall through the floor of your house. Newton's laws control how cars work, how water flows, how buildings don't fall down, and basically how everything around us moves.

It isn't always obvious how important these laws are, because to use them in complicated situations like getting ready for school, you need to know a lot of things, like the exact shape of your tube of toothpaste, how you squeeze on it, and what the toothpaste is made of. Newton's laws speak very generally all forces, but to use them for any specific problem, you have to actually know all the forces involved, like gravity, friction, and tension.

I'll give you a simple example from everyday life, which I chose because it doesn't have too many distracting details. For a car to move, there must be friction between the wheels and the ground. The wheels exert a force on the ground because they are spinning, and the ground exerts a reaction force on the wheels. It is this force which pushes the car forward. So thank Newton's law of action and reaction every time you drive somewhere!

If you decide to study physics in college, you'll definitely learn how to apply these laws to understand real-life problems! In high school classes, you usually do simpler examples like how a ball flies through the air. But even that is pretty important, if you like to play baseball! Luckily, humans naturally are good at understanding how things move, so you probably won't have to do any math problems to catch a baseball. If you want to land a spaceship on the moon, though, you'll have to study a lot harder!