AP Physics

Gravity Near the Earth's Surface

 

NY - 9.803 m/s2

Denver - 9.796 m/s2

North Pole - 9.832 m/s2

 

 

mg = GmmE
r2

g = GmE
r2

G = Gravitational constant = 6.67 x 10-11 Nm2/kg2

 

Ex) Mars has a mass 1/10 that of Earth and a diameter 1/2 that of Earth.  The acceleration of a falling body near the surface of Mars is most nearly

g = GmE
r2

 

 

 

 

Substitute changes into equation

Answer 4 m/s2

 

 

Giancoli p.  131) 32, 30

Earth - mass
5.974 x 10²⁴ kg

Earth - Mean Radius

6,371 km

 

Ex) Prove that the orbital velocity of satellite does not depend on the mass

mv2 = GmmE
r r2

 

 

v = (GmE/r)-1

From we equation we see that orbital V and Period T is only determined by orbital radius

The smaller the
radius the .....


the greater
the orbital velocity and

 smaller period T

 

Astronauts in Space Station
 are NOT weightless!!!

 

 



Enrichment

www.wpclipart.com

 

Einstein's Conception of Gravity

The Elegant Universe - PBS

 

 

 

Mythbusters Moon Landing Hoax 4 HQ

 


©Tony Mangiacapre., - All Rights Reserved [Home]
Established 1995
Use any material on this site (w/ attribution)