Newton's Laws of Motion

Newton's Laws of Motion, I think you have heard about it, not only heard you have studied it many times because we are studying it from 9th Class. But we have never applied it, actually this law is of very important with the application point of you. This is the basic laws which connect force and acceleration together. No, I don't mean it by saying that force is equal to mass multiplied by acceleration.
May be you know it but I must revise it once again the general definition of Newton's Law.
Newton's first law says that any body at rest remains at rest and any body moving with constant velocity moves with constant velocity (with constant speed in a straight line). unless disturbed by any external force.
This means in the absence of force we are not going to stop once we are imparted speed, but why it is not happening, object generally come to rest after traveling some distance if we give some initial velocity to it, by the help of newton's this law we are able to know that there are some forces acting in nature which make a body stop. Actually this law was not discovered by Galileo before newton gave it a systematical definition.
In the old time people were thinking that the natural state of any object is the state of rest but Galileo had told them that state of rest is not the natural state but motion with a constant velocity ( including the state of rest) is the natural state of object.

Newton's Second law says that a heavier body when given accelerate less than a lighter body when given equal amount of force, similarly if greater force is given more will be acceleration of any object.
This tells us that force is equal to mass multiplied by acceleration. We will see its application in the problem which will be posted later.

Newton's third law says that every action has equal and opposite reaction. This law seems to be very simple but it is not so simple as it looks from its definition. Like when you throw a ball to the wall it re bounces back toward you, now when you throw a ball with greater force (more harder) then it re bounces back with greater velocity, why this happens, when that balls strikes the wall it exert force on that wall and in return wall give equal but opposite force to ball which causes it to re bounce, more more ball will exert on the wall more will be given by wall to ball and so ball with re bounce more.
Now see that these two forces, (force that ball exert and force which wall exert) are known as action and reaction pair, and you can see that these forces always act on different object, like first force by ball act on wall and second force by wall act on ball. If they are not acting on different object means they are not action reaction force, while doing problems we will see different examples of this law where it will get difficult to find action reaction pair, but keeping this in mind that they always act of different object it will get somehow easier to find it.

if you are facing difficulties in the terms like velocity, acceleration, force, mass or anything read my later posts.
Download concept which will be required for problem solving Download