PHY100 Writing 1 - Assignment Example

PHY100 Writing Assignment Rubber band is formed from the naturally occurring polymer. In a piece of rubber band, the moleculesare all tangle up with each other when in outstretched state. When a rubber is stretched however, it loses its original shape because the curled molecules are driven apart. The rubber band is able to stretch because its molecules are tangled together in unstretched state thus elasticity occurs because the molecules curl up when released. Since a rubber band is made up of many polymer chains, when in relaxed state, the molecules have significant freedom of movement and vibration, however when it is stretched, its molecules have less vibrational energy thus less freedom of movement (Breithaupt, 76).

Changes in energy occur to the rubber band when it is stretched (application of force) and when it is in unscratched state. Hooke’s Low can be used to demonstrate the changes that take place in a rubber band when it is stretched. Hooke’s law states that “the amount of force applied to an elastic object is proportional to the amount of deformation (stretch or compression) that the object undergoes” (Breithaupt, 77). This is why when more force is applied on a rubber band, the stretch increases and when a little force is applied, there is little stretch.

This principle can be presented in the following equation where F represents the applied force, k represent the force constant of the rubber band and x is the length of the stretch recorded. In the equation below, the force applied is proportional to the amount of deformation on the rubber.F = kxDespite the fact that a rubber band is elastic and can stretch when more force is applied, the rubber band only stretches up to a certain limit. Robert Hooke also noted that elastic objects stretches until they reach elastic limit also referred to as yield limit.

Beyond this point, the rubber band exhibit plastic deformation and can no longer return to their original shape when the stretch force is removed. Plastic deformation occurs on the rubber band because beyond maximum stretch force, application of extra force results into breaking of limited number of atomic bonds holding together rubber band molecules (Fan & Zhu, 28). This explains why certain parts of the rubber band stretched more than the other parts. These parts that stretched more the other parts must have underwent plastic deformation.

Works CitedBreithaupt, Jim. Essential AS Physics for OCR. London: Nelson Thornes, 2004.Fan, Liang-Shih & Zhu Chao. Principles of Gas-Solid Flows: Cambridge Series in Chemical Engineering. Cambridge: Cambridge University Press, 2005.