In physics, a contact force is a force that acts at the point of contact between two objects, in contrast to body forces. Contact forces are described by Newton's laws of motion, as with all other forces in dynamics.
Contact force is the force in which an object comes in contact with another object. Contact forces are ubiquitous and are responsible for most visible interactions between macroscopic collections of matter. Pushing a car up a hill or kicking a ball or pushing a desk across a room are some of the everyday examples where contact forces are at work. In the first case the force is continuously applied by the person on the car, while in the second case the force is delivered in a short impulse. Certain contact forces describe specific phenomena and are important enough to have been given unique names. The most common instances of this include friction, normal force, and tension. According to forces, contact force may also be described as the push experienced when two objects are pressed together.
In the Standard Model of modern physics, the four fundamental forces of nature are known to be non-contact forces. The strong and weak interaction primarily deal with forces within atoms, while gravitational effects are only obvious on a macroscopic scale. Molecular and quantum physics show that the electromagnetic force is the fundamental interaction responsible for contact forces. The interaction between macroscopic objects can be roughly described as resulting from the electromagnetic interactions between protons and electrons of the atomic constituents of these objects. Everyday objects do not actually touch each other; rather contact forces are the result of the interactions of the electrons at or near the surfaces of the objects (exchange force). this also include friction
Famous quotes containing the words contact and/or force:
“Who among us has not, in moments of ambition, dreamt of the miracle of a form of poetic prose, musical but without rhythm and rhyme, both supple and staccato enough to adapt itself to the lyrical movements of our souls, the undulating movements of our reveries, and the convulsive movements of our consciences? This obsessive ideal springs above all from frequent contact with enormous cities, from the junction of their innumerable connections.”
—Charles Baudelaire (1821–1867)
“The event combined with
Beams leading up to it for the look of force adapted to the wiser
Usages of age, but it’s both there
And not there, like washing or sawdust in the sunlight,
At the back of the mind, where we live now.”
—John Ashbery (b. 1927)