Newton's 1^st Law

The first law deals with forces and changes in velocity. The first law of motion talks about the motion of a body for a particular situation. There is either "no force" or "zero net force" acting on the body. The first condition of "no force" is not common in our immediate surrounding. All bodies are acted by gravity i.e. force of attraction due to Earth. The second condition of "zero net force" is common in our immediate surrounding, where most bodies are stationary in Earth's reference as net force is zero. For just a moment, let us imagine that you can apply only one force to an object. That is, you could choose push the object to the right or you could choose to push it to the left, but not to the left and right at the same time, and also not up and to the right at the same time, and so on.

Under these conditions the first law says that if an object is not pushed or pulled upon, its velocity will naturally remain constant. This means that if an object is moving along, untouched by a force of any kind, it will continue to move along in a perfectly straight line at a constant speed. This also means that if an object is standing still and is not contacted by any forces, it will continue to remain motionless. Actually, a motionless object is just a special case of an object that is maintaining constant velocity. Its velocity is constantly 0 m/s .Imagine that two forces act at the same time on an object. One is a very strong force to the left, and the other is a weaker force to the right. These two forces add up to one net force. Since the force to the left is stronger, the net force is to the left. This net force to the left will cause the velocity of the object to change. The object experiences this one net force as if this was the only force pushing it, although, actually, there are two separate forces present.