Understanding Mass, Energy, and EM Radiation: Waves and Particles, Slides of Medical Genetics

Download Understanding Mass, Energy, and EM Radiation: Waves and Particles and more Slides Medical Genetics in PDF only on Docsity! Energy and Mass Introduction Docsity.com Mass • Mass−Measure of the resistance of a body to acceleration. – eg. • Newton’s 2nd Law amNewtonsF  =)( Docsity.com Electron-Volt • For 1 electron moving in a 1V potential difference, – • Define this as 1 electron-Volt (eV) ( )( ) JE 1818 106.11106.1 −− ×=×= Docsity.com Conservation of Mass • – c is the speed of light •     = 2 22)()( s mckgmJE s m810997925.2 × Docsity.com 1 amu = (1.66043 107” 2.997925 x 10°) 1 amu = 1.49232x10-7 Docsity.com Waves • Longitudinal waves—disturbance in the direction of propagation. – eg. sound Animation courtesy of Dr. Dan Russell, Kettering University Docsity.com • Transverse waves—disturbance perpendicular to direction of propagation. – eg. waves in the ocean Animation courtesy of Dr. Dan Russell, Kettering University Docsity.com • Regardless of the type of wave, they can be characterized by: – wavelength (λ) – frequency (f) – phase (φ) – velocity (ν) – amplitude λν f= Docsity.com Reriection “narmal place > . le gue Bee miror Cpependa ater to eiccor) (CSrall’s ) baw of RePlectisn = Of = Op Rereaction tg Maang tar) Cgtews) incederk cay : ers : = 3 yarrnet <8 transmitted if ny>ny 4ren 48, ray nena fen O,> Or (, beat foward normal qeing rate higher index bert “wy from pornal gens ‘inte tower index Docsity.com • Particle characteristics of EM radiation: – Particles of EM radiation are called quanta or photons. • Photons can be thought of as wave packets of electric and magnetic fields E  H  λ wavelength oscillatory electric field (force) s mc 8103×= λ ν hchEEnergyhotonP === perpendicular magnetic field (force) Docsity.com • h is Planck’s constant skeVsJh •×=•×= −− 1834 1013.41062.6 ( ) ( ) λ λ /1024.1 9−×== hckeVE Docsity.com EM Radiation Low E, long λ—Acts like wave. High E, short λ—Acts like particles. Docsity.com • Scientists have observed that electromagnetic radiation has a dual "personality." – Besides acting like waves. • It acts like a stream of particles (called "photons") that have no mass. – The photons with the highest energy correspond to the shortest wavelengths. Docsity.com • Electromagnetic waves are produced by the motion of electrically charged particles. – These waves are also called "electromagnetic radiation" because they radiate from the electrically charged particles. – They travel through empty space as well as through air and other substances. Docsity.com