Chapter2_12 - the earth: 2 2 / 8 . 9 s m R M G g earth...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
PHY3063 R. D. Field Department of Physics Chapter2_12.doc University of Florida Equivalence of Inertial and Gravitational Mass Inertial Mass: The inertial mass of an object tells us how difficult it is to change the particles velocity ( i.e. accelerate it). Can uniquely determine the inertial mass m of a particle relative to the reference mass m ref by applying an equal force to m and m ref and measuring the ratio of the resulting accelerations as follows: ref ref i a m F a m = = and ref ref i m a a m = . Gravitational Mass: The gravitational mass m g of a particle is determined ( at the surface of the earth ) by measuring the gravitational force exerted on it as follows: g m R M m G F g earth earth g grav = = 2 and g F m grav g = , where g is the acceleration due to gravity at the surface of
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: the earth: 2 2 / 8 . 9 s m R M G g earth earth = . Experiment: In a vacuum all bodies fall with the same acceleration. g m a m g m a m g i g i 2 2 2 1 1 1 ) ( ) ( ) ( ) ( = = Dividing the two equations gives = 1 2 2 2 1 1 ) ( ) ( ) ( ) ( a a m m m m g i g i and since a 1 = a 2 2 2 1 1 ) ( ) ( ) ( ) ( g i g i m m m m = . We see that m i /m g is the same for all particles and hence we can define G such that m i = m g for all particles. Only one type of mass! Earth M e R e Mass m g Cannon Ball Feather Release both at t = 0 Both hit ground at same time! Inertial Mass F m i Gravitational Mass Set equal to 1...
View Full Document

This note was uploaded on 05/29/2011 for the course PHY 3063 taught by Professor Field during the Spring '07 term at University of Florida.

Ask a homework question - tutors are online