# Kinetic Friction

Topics: Friction, Force, Classical mechanics Pages: 4 (1117 words) Published: February 3, 2010
Experiment 4: Friction
Laboratory Report

Anna Rucelli Ignacio
Michael Giorgio Lapus
Ted William Lardizabal
Janell Leica Lee

Department of Occupational Therapy
College of Reabilitation Sciences, University of Santo Tomas España, Manila Philippines

Abstract

The experiment verifies the laws of friction with the use of a spring scale, a block of wood, its different surfaces and the different surfaces of other objects. Another part of the experiment uses the palms of the hands to produce friction then apply lubricants then see the differences. The experiment also observes the effect of air resistance on falling paper.

1. Introduction

Friction is the force resisting the relative lateral (tangential) motion of solid surfaces, fluid layers, or material elements in contact. It is usually subdivided into several varieties:

* Dry friction resists relative lateral motion of two solid surfaces in contact. Dry friction is also subdivided into static friction between non-moving surfaces, and kinetic friction (sometimes called sliding friction or dynamic friction) between moving surfaces.

* Lubricated friction or fluid friction resists relative lateral motion of two solid surfaces separated by a layer of gas or liquid.

* Fluid friction is also used to describe the friction between layers within a fluid that are moving relative to each other.

* Skin friction is a component of drag, the force resisting the motion of a solid body through a fluid.

* Internal friction is the force resisting motion between the elements making up a solid material while it undergoes deformation.

Friction is not a fundamental force, as it is derived from electromagnetic force between charged particles, including electrons, protons, atoms, and molecules, and so cannot be calculated from first principles, but instead must be found empirically. When contacting surfaces move relative to each other, the friction between the two surfaces...