Forces are the reason an object moves, stops, and accelerates (speeds up). Every single second we interact with forces of attraction and repulsion.
Newton’s laws of motion
Isaac Newton published his Philosophiae Naturalis Principia in 1686. He presented three laws of motion in this Principia. This awesome laws can predict and describe motion precisely.
Newton’s first law
This law states that: Every body persists in a state of rest or of uniform motion in a straight line unless it is compelled to change that state by forces impressed on it.
This law simply says that an object will continue to stay at rest unless forced to move by an external force. As you know your book wouldn’t move across the table on its own, someone or some force, would have had to move it. Even a moving ball would tend to stay that way unless forced to stop. Someone’s probably thinking “but when I kick my football it always come to a stop with nothing acting on it.” or something similar. Even if it appears that way, there’s a force acting on it, friction (search my posts for friction if you want to learn more). Friction is forcing the ball to rest. Also, a moving object always travel in a straight line so no matter how hard you spin a ball before letting go, it will always fly off on a straight line, you might be thinking of some scenario that this “didn’t happen” maybe spinning a rock with a string (or something similar). In this case the rock is being forced to move because of the force acted on it by the string.
Newton’s second law
It states that the force applied to an object equals the time rate of change in momentum. Or simply: the force applied to an object is directly proportional to its mass and acceleration ( that is, increases with its acceleration) this can be derived from the initial law.
Newton’s third law
This laws states that for every action there is an equal and opposite reaction. This law applies for ever action we do literally, walking, sitting, name it. Any force applied to something has an equal force acting in the opposite direction.
Types of forces
There are four fundamental forces of nature. (1)The strong force: the strongest of all. The force exists within an atoms nucleus. It is the force that holds an atoms nucleus together. It is a short range force. (2) The electromagnetic force: this force exists between two electrically charged bodies. It is either an attractive (between unlike charges) or repulsive force (between like charges). The electromagnetic force is inversely proportional to the square of the distance between the charge bodies. (3) The weak force: this force is responsible for certain particle interactions in the radioactive decay of atomic nuclei. (4) The gravitational force: this force is the weakest, think about this, it takes the entire earth to pull a pen to the ground, but a child can easily counteract its force by lifting the pen. This force exists between matter.
Note that some of this forces will be explained in greater detail in upcoming blogs. Thanks for reading.
