Levitating Slinky

If you drop a dangling slinky, you would expect it to just fall to the ground but that is not what happens. What actually happens is that the bottom just hovers for a moment until the top collapses on top of it as seem in the video There are two main reasons why this occurs.

This first has to do with newtons law of action reaction. As top falls the spring of the slinky is pulls it down faster the pull of gravity. At the same time the spring is pulling the bottom up countering the pull of gravity. As a result the bottom remains  suspended until the top collapses on to it ending the action reaction effect.

The second is that because the bottom of the slinky is held up by tension and it take the time needed for the top to collapse for the bottom to get the message that the top was dropped.

Moving Things by Force

That which causes a free body to undergo acceleration is called foece.

There are four fundamental forces in Nature. They are gravity which is the mutual attraction of all matter in the universe it is what holds you to the Earth, electromagnetism which is the mutual attraction and repulsion of charged partials, the weak nuclear force is that which regulates types of nuclear decay such as Bata decay by overcoming the strong nuclear force and the strong nuclear force is the binding force that holds the atomic nucleus together against the tendency of positively charged protons.

Force causes mater to accelerate which is the main function of force by definition. It can be used to overcome other forces such as friction gravity. Force also holds things together since the electromagnetic force holds an object together including your body and the strong nuclear force holds atomic nuclei together. It can break things apart such as bombs or the force resulting from ramming two things together which can cause them to shatter and the peaces to fly apart.
Regardless of its source force causes acceleration. Force can also stop acceleration by resisting another force. Force holes thing together so force does indeed bind us together

What's Matters in Physics

Anything that has mass and occupies volume is called Matter:. In general it is the substance of which all physical objects are made. Mass is in the generally sense it is the amount of matter in an object. It is the term for two properties of matter that are equal in value: inertial mass gravitational mass. Inertial Mass is the resistance of a body to acceleration when responding to force. Gravitational Mass is  the property of an object that determines the strength of its gravitational field and its reaction to gravity.

The existence of a relationship between the inertial and gravitational mass of an object is evident from the fact that they have same the value. However General Relativity shows that inertial and gravitational mass are two aspects of the same thing. Special Relativity shows that an objects mass is equivalent to the amount of energy an object contains.

Normal Matter is composed of atoms. Atoms are a nucleus; made of protons and neutrons; with electrons around it. This form of matter in what we commonly experience. Matter makes up everything around us, everything we see, everything we touch and even our bodies. Matter is one of the three main parts of the Universe Space, Time and Mass. (matter) Relativity shows them to be inter-related in that space and time are so interrelated that they form a single entity called space-time. Furthermore mass warps space-time forming gravity and the motion of mass contracts both space and time. In common experience matter is what makes up objects around us and Physics has shown that it to be a lot more. Matter is a fundamental part of the universe.