How does a noncontact force create a force against an object?

Answer 1

It is helpful to consider that some forces express themselves in what is called a field, and this field "surrounds" the object that has that force associated with it. We're familiar with a couple of the basic forces that do this, and gravity is one such force, while electromagnetic force is another. Let's look at them. If we consider gravity, it is reaching from the sun to all the planets (and other things in solar orbit) and is holding onto them. Earth is some 93 million miles from the sun, but the sun has held it in orbit for billions of years. Gravity can reach through the vacuum of space and grab a hold of things. It does, and we're glad for its effects. In electromagnetics, we see that the magnetic force reaching its invisible field lines out around the source to interact with ferromagnetic materials around it. If we have a sheet of glass, iron filings and a magnet, we can set up a demonstration. We can put the magnet below the sheet of glass to move the iron filings on the glass. The magnetic field (the field lines) will "reach through" the glass to interact with the iron filings, and we see the effects when we move the magnet. The forces are expressed in the field that is the "force carrier" of the "thing" that has the force associated with it. If we think of the "force field" around the object that has the force associated with it, then it is easier to see that the field can interact with other objects or materials. And it can do so without the object with which the force is associated having to be in contact with other objects on which the force is acting.

Answer 2

A noncontact force can create a force against an object through fields such as electromagnetic fields or gravitational fields. These fields can exert a force on an object without direct physical contact, attracting or repelling the object based on their properties.