ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: TonyHem on February 27, 2009, 08:25:36 pm

Title: Satellites
Post by: TonyHem on February 27, 2009, 08:25:36 pm: The space shuttle is launched into orbit from a point A on the equator as shown. The shuttle then enters a stable circular orbit of radius Ro at point B. The radius of the Earth is 6.4 x 10^6 m. The ratio of the gravitational field strength at A to that at B is equal to 1.2. Calculate the distance Ro.

There's a diagram - can't really get it up but its page 98 in the Heinemann physics 12 book if anyone has it.
Title: Re: Satellites
Post by: Mao on February 27, 2009, 09:14:36 pm: strength at A: $g_A=\frac{GM}{(6.4E6)^2}=1.2g_B$

strength at B: $g_B=\frac{GM}{R^2}$

hence, $\frac{GM}{(6.4E6)^2}=1.2\times \frac{GM}{R^2}$

$\implies R^2 = 1.2\times (6.4E6)^2$

$\implies R=7.0\times 10^6\; m$
Title: Re: Satellites
Post by: TonyHem on February 27, 2009, 10:36:49 pm: k thanks get it now :)