What are force and motion?

Answer 1

As regards forces, there are four fundamental forces in the universe. They are gravity, the electromagnetic force, and the strong interaction (strong force) and weak interaction (weak force). Just the four. This is basic physics, and it is fundamental to understand this foundational idea. Now on to the other applications of the word force in physics. A fundamental concept of physics is mechanics. The idea of force is that it can be used to create motion, or to move things. A force (F) applied to an object that isn't "stuck" will impart motion to the object. The object has some amount of mass (m) associated with it, and the force will accelerate (a) the mass. Note that force has magnitude (an amount) and also a direction (a direction vector). A force has both "strength" and "direction" to it. Motion is the movement of something through or across spacetime. When something changes its physical location, its position, it is said to have moved. It changes location as time passes. Lots of things are moving, are in motion, and their position in space changes over time because of their motion. A force (F) accelerates an object or a mass (m), and gives it motion, or gives it an acceleration (a), according to this equation: F = m times a If you prefer to look at it another way, force divided by mass equals acceleration. More force on a given mass means more acceleration on that mass. More mass acted on by a given force means a reduced acceleration compared to a smaller mass acted on by that same force. Very logical and intuitive, and very correct. Just what you'd expect. In case it wasn't clear, because force has a direction associated with it, acceleration will also have a direction associated with it. The only missing piece of the puzzle is velocity, which is speed (as in distance per unit of time) plus that direction vector we spoke of. Force, acceleration and velocity all have "direction" or a direction vector associated with them. Speed doesn't have to have a direction vector. An object can move at a constant speed as a ball whirling around on a string, and be constantly changing velocity because it is accelerated by the string to "stay in its arc" as it moves. The ball has constant speed, and constantly changing velocity because of the constant acceleration of the string. We cover all these things in the physics topic of mechanics, as stated. Wikipedia has more information and many more particulars, and a link is provided to their posts on force and motion.

Answer 2

Force may be defined simply as a push or pull. Motion is the movement of an object brought about by force.