• Editor H

Physics and Math - 1. Introduction

Introduction


This appendix discusses selected aspects of biophysics, the study of physics as it applies to biological systems. Because living systems are in a continual exchange of force and energy, it is necessary to define these important concepts. According to the seventeenth-century scientist Sir Isaac Newton, a body at rest tends to stay at rest and a body in motion tends to continue moving in a straight line unless the body is acted upon by some force (Newton’s First Law).


Newton further defined force as an influence, measurable in both intensity and direction, that operates on a body in such a manner as to produce an alteration of its state of rest or motion. Put another way, force gives energy to a quantity, or mass, thereby enabling it to do work. In general, a driving force multiplied by a quantity yields energy or work. For example:


force * distance = work


Energy exists in two general forms: kinetic energy and potential energy. Kinetic energy {kinein, to move} is the energy possessed by a mass in motion. Potential energy is energy possessed by a mass because of its position. Kinetic energy (KE) is equal to one-half

the mass (m) of a body in motion multiplied by the square of the velocity (v) of the body:


KE = 1/2 mv²


Potential energy (PE) is equal to the mass (m) of a body multiplied by acceleration due to gravity (g) times the height (h) of the body above the earth’s surface:


PE = mgh, where g = 10 m/s²


Both kinetic and potential energy are measured in joules.



Richard D. Hill and Daniel Biller University of Texas


IWL 아카데미

(02) 553 1125

서울 강남구 테헤란로 51길18 광진빌딩

All Rights Reserved ©2019 iwrote.life